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1.	André, Alann, 1980, et al. (författare) Flax Fiber-Reinforced Glued-Laminated Timber in Tension Perpendicular to the Grain: Experimental Study and Probabilistic Analysis 2010 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 22:9, s. 827-835 Tidskriftsartikel (refereegranskat)abstract The weak mechanical properties of wood in tension perpendicular to the grain are often the origin of catastrophic brittle failure. In order to enhance the tension strength perpendicular to the grain and achieve a more ductile failure, flax fibre and glass fibre reinforced polymer (FRP) composites were used to strengthen glued-laminated (glulam) timber specimens. Three series of specimen of glulam timber (flax fibre reinforced, glass fibre reinforced and unreinforced), with a grand total of 28 specimens, were tested in tension perpendicular to the grain. For an approximate amount of FRP reinforcement of 1.2- in volume (thickness ~ 0.7 mm), an increase of the tensile strength up to 74- was shown, with a stiffness increase up to 41-. For all reinforced specimens, semi-ductile failures were observed. A parametric study was carried out using both the Monte Carlo method (MC) and the First Order Second Moment method (FOSM). It is shown that the mean values obtained during experiments are in agreement with those from the MC simulation. However, the standard deviations from the MC simulation are larger. From the FOSM analysis, it is demonstrated that the variation in glulam stiffness perpendicular to the grain is not the first parameter driving the variation for the reinforced system. The variation in mechanical properties of the flax fibres appeared to be the driving parameters for the strength of the system.
2.	Williams Portal, Natalie, 1986, et al. (författare) Sustainable Potential of Textile-Reinforced Concrete 2015 Ingår i: Journal of Materials in Civil Engineering. - 1943-5533 .- 0899-1561. ; 27:7 Tidskriftsartikel (refereegranskat)abstract The building construction industry is in need of sustainable materials and solutions. A novel building material, such as textile-reinforced concrete (TRC), could be used to meet this demand. TRC is a combination of fine-grained concrete and multi-axial textile fabrics, which has been fundamentally researched over the past decade. TRC-based research has explored various facets of this composite material, such as its structural functionality, production, applicability and design. One key aspect that is still missing, however, is a comprehensive review of the sustainable potential of this material in terms of its input-output and durability which suitably answers to requirement no.7 of EU’s Construction Products Regulation. This article provides qualitative and quantitative evaluation of the sustainable potential and prospective development of TRC particularly reinforced by alkali-resistant (AR) glass, carbon or basalt fibers. Based on the outcome of this evaluation, carbon textile fibers were observed to hold the optimal potential mechanical behavior; additionally, it was revealed through the conducted Life Cycle Assessment (LCA), that basalt had the least cumulative energy demand while carbon had the least environmental impact.
3.	Johannesson, Björn, et al. (författare) Test of four different experimental methods to determine sorption isotherms 2002 Ingår i: Journal of Materials in Civil Engineering. - 0899-1561 .- 1943-5533. ; 14:6, s. 471-477 Tidskriftsartikel (refereegranskat)abstract One important property of materials is their moisture fixation capacity, i.e., their ability to hold moisture at different relative humidities. The sorption isotherm is one of the main input data in moisture diffusion models, and it can also be used to evaluate properties of the microstructure. We have used four different methods to measure the sorption isotherm of sandstone and porous glass. The first method was to equilibrate samples over saturated salt solutions. The second was a sorption balance in which small material samples were weighed as they were exposed to different relative humidities. The third method was the pressure plate extractor, in which a totally wet sample was equilibrated at various overpressures, corresponding to certain relative humidities. The fourth method was a newly developed microcalorimetric technique to measure sorption isotherms. Despite the different natures of the methods, a satisfying agreement was found. (10 refs.)
4.	Bekele, Abiy, et al. (författare) Application of Energy-Based Crack Initiation Approach to Low-Temperature Damage and Recovery Based on Noncontact Resonance Testing 2020 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 32:9 Tidskriftsartikel (refereegranskat)abstract Low temperature has a tendency to cause microdamage in asphalt concrete because of the relative thermal contraction of mastic and subsequent accumulation of thermal stresses. This paper presents the applicability of an energy-based micromechanical approach for assessing low-temperature damage and recovery in asphalt concrete based on a newly developed noncontact resonance testing. The principle of local energy balance and redistribution was applied to estimate average thermal microcrack length by considering local thermal strain energy release zones and surface energy of cracks initiated at preexisting air voids. A damage probing test was carried out by thermal loading and unloading of five different asphalt concrete specimens. The test was carried out by using a recently developed noncontact resonance method. The stiffness modulus was determined from the resonance test and utilized in the energy balance and redistribution formulation. Coefficients of thermal contraction of the specimens were also determined based on the noncontact resonance test and by applying the principle of the impact-echo method and calculating changes in thickness of the test specimens.
5.	Bhanbhro, Riaz, et al. (författare) Mechanical Properties and Particle Breakage of Uniform-Sized Tailings Material 2021 Ingår i: Journal of materials in civil engineering. - Luleå : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 33:3 Tidskriftsartikel (refereegranskat)abstract Tailings dam disasters are reported almost every year and are triggered by mechanisms, such as overtopping, piping, and others.The failures due to inadequate management cannot be neglected as well. These dams are constructed mostly in a step-by-step constructionmethod that leads to a continuously changing state of vertical loads during construction and may lead to particle breakage and changes instrength. Therefore, a layer of tailings dam today may not be the same tomorrow during the construction phase. To study the effects ofdifferent loads on particle breakage and strength, direct shear tests were performed on remolded tailings samples that were separated intodifferent particle sizes. The tests were performed using different normal stresses that ranged from 50 to 500 kPa. The results indicate that finertailings exhibited slightly more shear resistance than that of coarser tailings irrespective of the deposition method. For normally depositedspecimen, the dilatant and contractant behavior in vertical height was observed when the normal effective stress was less than 300 kPa andgreater than 300 kPa, respectively. Under the vertical deposition method, the finer tailings showed contractant height behavior when subjectedto a normal effective stress of 300 kPa. The friction angle and the cohesion of vertically deposited specimens were slightly higher and slightlylower, respectively, than that of normally deposited ones. The breakage of tailings particles was observed to be proportional to the particle sizeof the tailings.
6.	Buasiri, Thanyarat, et al. (författare) State of the Art on Sensing Capability of Poorly or Nonconductive Matrixes with a Special Focus on Portland Cement–Based Materials 2019 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 31:11 Tidskriftsartikel (refereegranskat)abstract Concrete is a well-established and the most used but also well-characterized building material in the world. However, many old and new-build structures suffer from premature failures due to extensive deterioration and decreased load-bearing capacity. Consequently, structural monitoring systems are essential to ensure safe usage of concrete structures within and beyond the designed life. Traditional monitoring systems are based on metallic sensors installed in crucial locations throughout the structure. Unfortunately, most of them have a relatively low reliability and very short life span when exposed to often very harsh environments. The ideal solution is therefore to develop a smart concrete having itself self-sensing capability. A number of studies show that conductive cementitious matrixes will undergo changes in their electrical resistivity with variations of stresses, strains or, developing microcracking. This can be used as a reliable tool to measure changes. This review provides a comprehensive overview of several non-conductive matrixes, with special focus on Portland cement based materials showing self-sensing capabilities by description of detection mechanisms, sensing capabilities, limitations and potential applications.
7.	Cwirzen, Andrzej, et al. (författare) Effect of baltic seawater and binder type on frost durability of concrete 2014 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 26:2, s. 275-282 Tidskriftsartikel (refereegranskat)abstract The effects of Baltic seawater on frost durability of PC concretes using sulfate resistant portland cement and combination of rapid hardening portland cement with silica fume were studied. The freeze-thaw cycles were performed on specimens exposed to the Baltic seawater, 3% sodium chloride solution and deionized water. The freeze-thaw cycles appeared to cause the most extensive internal damage in specimens based on sulfate resistant cement (SR) and exposed to seawater. The most extensive surface scaling was observed in the case of concretes containing silica fume and exposed to deicing salts. Based on the thermo gravimetric and X-ray diffraction analyses it was concluded that extensive internal damage of concrete based on SR was caused by changes of the microstructure due to secondary formation of ettringite, carbonation, and formation of calcite. The results showed also that low C3A content of the SR did not fully mitigate formation of secondary ettringite during freeze-thaw cycles. A combination of rapid hardening portland cement and silica fume appeared to form more frost resistant concrete when exposed to seawater. © 2014 American Society of Civil Engineers.
8.	Cwirzen, Andrzej, et al. (författare) Effects of reactive magnesia on microstructure and frost durability of portland cement-based binders 2013 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 25:12, s. 1941-1950 Tidskriftsartikel (refereegranskat)abstract The effects of portland cement (PC) replacement with magnesia (reactive magnesium-oxide) on properties of PC-based pastes, mortars, and concretes were investigated. The research included determination of mechanical properties and frost durability in addition to studies of the microstructure and microchemistry. The mortar and paste mixtures contained from 10-80 weight percent (wt%) replacement of PC by magnesia and had water to cementitious-binder ratios from 0.4-0.7, whereas concretes contained from 5-10 wt% magnesia and had a water to cementitious-binder ratio of 0.53. Replacement of PC by magnesia had adverse effects on the mechanical properties and frost durability. The magnesia reduced microcracking of the binder matrix in comparison with pastes containing only PC. The primary hydration product of magnesia was brucite in addition to regular hydration phases of PC. The amount of formed portlandite was increased. Magnesia caused densification of the microstructure but also increased the capillary porosity, resulting in lower frost-durability. © 2013 American Society of Civil Engineers.
9.	Edvardsson, Karin, et al. (författare) Impact of fine materials content on the transport of dust suppressants in gravel road wearing courses 2011 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 23:8, s. 1163-1170 Tidskriftsartikel (refereegranskat)abstract A significant problem when dust-suppressing agents are used on gravel roads is that they tend to leach during rainfall. The purpose of this study is to illustrate this problem by using laboratory studies and studies in situ. Both capillary rise and leaching of suppressants were examined by using cylinders filled with wearing course material. Chloride was more prone than lignosulphonate to transport upwards by means of capillary rise, and therefore, it showed a more effective performance over a longer period of time. Optimal percentages of fine material for minimal lignosulphonate and chloride leaching were found to be 15% by weight and 10-15% by weight, respectively. Ions of calcium chloride seemed to flocculate clay particles, which probably prevents them from leaching. To study the in situ longevity of fine material in general, calcium carbonate, mesa, was used as a marker. The fine material in gravel wearing courses must be replenished regularly. Mesa loss was up to 80% after 1 year.
10.	Gschösser, Florian, et al. (författare) Life-Cycle Assessment of the Production of Swiss Road Materials 2012 Ingår i: Journal of Materials in Civil Engineering. - 1943-5533 .- 0899-1561. ; 23:2, s. 168-176 Tidskriftsartikel (refereegranskat)abstract Sustainable development demands contributions across all economic sectors. Thus, the infrastructure field, in this case road infrastructure, also has to contribute its part by generating road materials and road construction with lower environmental impacts. This paper analyzes the environmental potentials hidden in road materials used in Swiss road pavements. For several materials used in road construction, cradle-to-gate life-cycle assessments (LCA) were performed, taking into account all environmental impacts from raw material extraction to the finished product at the production plant. Environmental improvement potentials were analyzed for the production of asphalt mixtures, concrete mixtures, and subbase mixtures, using eight different environmental impact indicators. The results show differences in the environmental impact between best case and current status production setup of up to 54% for asphalt mixtures, 38% for concrete mixtures, and 93% for subbase mixtures.
11.	Humad, Abeer M., et al. (författare) Creep and Long-Term Properties of Alkali-Activated Swedish-Slag Concrete 2021 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 33:2 Tidskriftsartikel (refereegranskat)abstract The construction of the future is moving in the direction of environmentally friendly materials and the use of various types of industrial byproducts and wastes. The use of blast furnace slag (BFS) for the production of concrete is one of those alternatives. In this study, pastes and concretes based on high-MgO BFS were alkali activated with 10% by weight sodium carbonate, sodium silicate, and a combination of both. Heat treatment and laboratory curing were applied. The results showed that heat treatment was effective at reducing the drying shrinkage of alkali-activated slag concretes and promoting high early strength. However, the sodium carbonate–activated slag concrete specimens showed a reduction in compressive strength at later ages. All concrete specimens tested exhibited high drying shrinkage; the highest values were for sodium silicate–activated concretes and the lowest were for sodium carbonate–activated concretes. All concretes tested showed very large creep, which was partly related to the small maximum aggregate size (8 mm) and the effects of carbonation. The carbonation depth after 12–24 months was significantly smaller for the heat-treated specimens and for concrete activated with sodium silicate. The carbonation process resulted in a more porous binder matrix, leading to long-term strength loss and increased creep, especially for sodium silicate–activated mixes.
12.	Jensen, Jorgen L., et al. (författare) Brittle Failures in Timber Beams Loaded Perpendicular to Grain by Connections 2015 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 27:11 Tidskriftsartikel (refereegranskat)abstract A state-of-the-art review of simple analytical fracture mechanics models for calculation of the splitting capacity of timber beams loaded perpendicular to the grain direction by connections is presented. It is shown that most of the already available models are closely related and appear naturally as special cases of the most general model available. A new model, which is a semiempirical extension of an existing model based on a beam-on-elastic-foundation theory, is proposed. The so-called van der Put model, which forms the theoretical basis for the splitting equations used in the European and Canadian timber design codes, appears as a special case of the proposed model. The treatment of the splitting problem in some major timber design codes is reviewed and discussed based on the theoretical models and new test results. The approach used in the European timber design code where the maximum shear force on either side of a connection is considered rather than the total load applied on a connection is not in agreement with the test results presented. While the European and Canadian timber design codes apply a constant value for a material property related to the splitting performance irrespective of the material considered, the presented experimental results indicate that the material property for Radiata pine laminated veneer lumber can be close to twice the value for Douglas fir glulam. The presented test results also show that despite the fact that Douglas fir glulam has a significantly higher mean perpendicular-to-grain tensile strength than Radiata pine laminated veneer lumber, the splitting failure load of Radiata pine laminated veneer lumber is nevertheless significantly higher than that of Douglas fir glulam. The latter finding seems to be in disagreement with the German timber design code, according to which the splitting strength is proportional to the perpendicular-to-grain tensile strength. (C) 2015 American Society of Civil Engineers.
13.	Kim, Hyunwook, et al. (författare) Numerical and Experimental Analysis for the Interlayer Behavior of Double-Layered Asphalt Pavement Specimens 2011 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 23:1, s. 12-20 Tidskriftsartikel (refereegranskat)abstract Bonding characteristics between pavement layers have an important influence on responses of pavement structures. This paper deals with this subject by analyzing the interlayer behavior of double-layered asphalt (DLA) specimens taken from an in-service motorway using a coaxial shear test (CAST) and a layer-parallel direct shear (LPDS) test. To analyze and model the influence of the interlayer condition, finite-element simulations of CAST DLA specimens were conducted. In the models, both idealized fully bonded and no-bonding assumptions were used to characterize the interlayer behavior of DLA specimens. Experimental results presented for CAST and LPDS tests demonstrate that there is a strong influence of temperature in the interlayer bonding mechanism. At lower temperatures, there is an increase on the bonding strength produced by the binder stiffening and aggregate interlocking. Further, it was observed that comparisons of CAST experimental and numerical results indicate that the interlayer can be close to the fully bonded condition at low temperatures below 20 degrees C while the interlayer, at higher temperatures, behaves between fully bonded and no-bonding idealized conditions.
14.	Kuttah, Dina K, 1975-, et al. (författare) Performance Assessment of Hot-Asphalt Mixtures Produced with By-product Aggregates under Repetitive Heavy Traffic Loading 2019 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 31:6 Tidskriftsartikel (refereegranskat)abstract Given the importance of overcoming the challenges associated with the management of nonrenewable resources, and to solve the industrial waste stream problems, this article presents the results of fundamental research conducted to assess the rutting and fatigue cracking performance of hot asphalt mixtures with high percentages of by-product aggregates. For this purpose, two full-scale flexible pavement test sections were constructed and tested at the accelerated loading facilities at VTI (Swedish National Road and Transport Research Institute). The accelerated test aimed at evaluating the performance of two developed asphalt mixtures, designated as mix 1 and mix 7, and made up of 98% of industrial by-products (namely, steel slag, foundry sand (WFS), and reclaimed asphalt pavement, in addition to biobased additives). The test sections were constructed in an indoor facility and loaded with a heavy vehicle simulator (HVS) equipped with a half-standard truck axle with dual wheels. The two road sections were constructed using the same construction materials obtained from the same source, as follows: asphalt surface layer of 50-mm thick, 70-mm thick granular base layer, and 160-mm thick subbase layer on top of a 2.6-m thick sandy subgrade soil. Horizontal asphalt strain sensors were embedded in the pavement test sections to assess the mixture's resistance to fatigue and cracking and the laser surface profiler measurements were used to evaluate the rutting performance under controlled testing conditions. For comparison purposes, the long-term rutting developed in the sections paved with mix 1 and mix 7 was compared to the rutting observed in a previous similar HVS test carried out on a 70-mm thick asphalt surface layer section made only with natural virgin aggregates.The test results showed that mix 1 and mix 7 may suffer from higher rutting at the beginning when the road is open to traffic, as compared to asphalt mixtures of natural aggregate, but subsequently the alternative mixtures resisted the rutting development better with the increase of traffic loading as compared to the conventional asphalt mixtures. The horizontal strain measurements at the bottom of the asphalt layer during testing showed that failure began as cracks initiated at the bottom of the asphalt layer of mix 7 and started to propagate to the surface of the asphalt layer in the last stage of the HVS traffic loading of the test. No fatigue cracking was observed in the asphalt surface paved with mix 1 at the end of heavy vehicle simulation (HVS) testing. The study demonstrated that the adopted by-product hot mix asphalt (HMA) mixtures can substitute the conventional HMA material under the given heavy traffic loading and environmental conditions.
15.	Long, Wujian, et al. (författare) Durability of Slag-Cement Paste Containing Polyaluminum Chloride 2021 Ingår i: Journal of Materials in Civil Engineering. - 1943-5533 .- 0899-1561. ; 33:9 Tidskriftsartikel (refereegranskat)abstract The effect of polyaluminum chloride (PAC) on the durability, microstructure, and corrosion sensitivity of slag-cement pastes was investigated in this research. Various experimental tests were performed to assess the mechanical properties (compressive strength test), durability (rapid chloride migration test, water permeability test, capillary water absorption test, chloride binding test, accelerated carbonation test), microstructure (scanning electron microscopy, X-ray diffraction, mercury intrusion porosimetry), and corrosion sensitivity (accelerated corrosion sensitivity, initial chloride concentration). Experimental results showed that adding 1.5% PAC increased compressive strength by 77.0%, 53.8%, and 19.4% at 3, 7, and 28 days. Resistance to chloride migration, water permeation, capillary water absorption, and carbonation was improved. These results were consistent with the microstructural analysis, which showed that adding PAC facilitated the formation of Friedel's salt and development of pore structure, which was the key factor for the improved durability of the slag-cement paste. Adding 1.5% PAC had a limited influence on the corrosion sensitivity despite introducing the additional chloride ions into the system. These results promote the further practical application of PAC.
16.	Malaga, Katarina, et al. (författare) Relevance of hydrophobic and oleophobic properties of antigraffiti systems on their cleaning efficiency on concrete and stone surfaces 2013 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 25:6, s. 755-762 Tidskriftsartikel (refereegranskat)abstract The problem of graffiti is not entirely restricted to urban areas, but also appears frequently in rural communities and along traffic infrastructure. Besides its aesthetic and societal effects, graffiti cause considerable removal costs and subsequent costs for repairing damages caused by improper graffiti removal. Over the last two decades, strategies have been developed to combat graffiti in the built environment, including the development of protective measures in the form of antigraffiti systems (AGSs). Antigraffiti systems promise to be affordable and easily applicable for a wide range of substrates, and many products have already been on the market for many years. In practice, however, successful application of AGS and removal of graffiti depend on many factors in which the type of coating and condition of the substrate play critical roles. The optimal environmental goal is to use AGS without any cleaning chemicals except for pure water. Available studies on the behavior of the same AGS on various substrates can show completely different results concerning the cleaning efficacy and the durability of the AGS under different climatic conditions. The question of which properties of an AGS are most essential for its efficiency has still not been fully investigated. The goal of this study was to investigate cleaning efficacy in conjunction with hydrophobic and oleophobic properties of the AGS on different substrates. The results showed that hydrophobicity and oleophobicity are important for dense substrates but have a low influence on porous substrates. In this case, cleaning efficiency is majorly determined by the physical properties of the substrates.
17.	Miccoli, Lorenzo, et al. (författare) Static behavior of cob : Experimental testing and finite-element modeling 2019 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 31:4 Tidskriftsartikel (refereegranskat)abstract The aim of this paper is to implement a numerical model to reproduce the nonlinear behavior of cob walls under shear loading. Axial compression, pull-off, and diagonal compression tests were carried out to derive the mechanical parameters. In addition, the stressstrain relationships, the nonlinear behavior, and the failure modes were defined. The experimental results were then used to calibrate a finiteelement model. The material behavior was simulated through a macromodeling approach adopting the total strain rotating crack model. A sensitivity analysis was conducted to assess the effects of varying the parameters with higher uncertainty on the structural behavior. The numerical model achieved good correspondence with the experimental results in terms of simulation of the shear stress-shear strain relationship and of damage pattern.
18.	Osman, Dalia Ahmed Mohammed, et al. (författare) Reduction of Energy Consumption in Cement Industry Using Zinc Oxide Nanoparticles 2020 Ingår i: Journal of materials in civil engineering. - : ASCE-AMER SOC CIVIL ENGINEERS. - 0899-1561 .- 1943-5533. ; 32:6 Tidskriftsartikel (refereegranskat)abstract The present study investigates the possibility of introducing zinc oxide nanoparticles into the cement raw mix so as to reduce the energy consumption and CO2 emissions during processing. Zinc oxide nanoparticles are prepared via a hydrothermal growth method using zinc acetate dihydrate and sodium hydroxide as precursors. The percentages of zinc oxide nanopowder added to the cement raw material was varied between 1% and 3%. The resulted clinker and cement samples were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), and compressive strength tests. It is concluded that the addition of 1% synthesized zinc oxide nanopowder into portland cement production improves the burnability of the cement raw mixture. A reduction of clinker temperature up to 1,300 degrees C, instead of the 1,450 degrees C-1,500 degrees C usually required, was achieved, thereby enabling a reduction in both energy consumption and greenhouse gas emissions. The 28-day strength is within the target design compressive strength of 42.5 N/mm(2). (c) 2020 American Society of Civil Engineers.
19.	Prapoorna Biligiri, Krishna, et al. (författare) Prediction of the Remaining Fatigue Life of Flexible Pavements Using Laboratory and Field Correlations 2015 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 27:7 Tidskriftsartikel (refereegranskat)abstract The main objective of this study was to develop comprehensive criteria to evaluate the remaining service life of existing roads as regards their field fatigue cracking characteristics using fracture mechanics principles and associated laboratory performance tests. Two basecourse layers were investigated for their residual fatigue lives: reference and modified stone mastic asphalt mixes. The two pavement systems’material characteristics using the actual field cores were estimated in the laboratory, including moduli, fatigue relationships, and crack propagation parameters. Additionally, field measurements encompassed collection of falling weight deflectometer deflections, temperature variations, and traffic counts. Fatigue lives of the two base course layers were predicted using the developed laboratory-based fatigue and crack propagation parametric relationships during one climatic period. The modified structure presented significantly longer fatigue life than the reference mix. This was indicative of the findings that the laboratory procedure(s) based on asphalt mixture properties’ fracture and fatigue mechanics such as crack initiation, and propagation modeling and relationships are useful for evaluating the pavement mix’s performance in the field as well. Overall, laboratory tests provided reliable information regarding residual life predictions in case it is difficult to actually perform field measurements and estimate the residual life of a pavement system. The criteria developed in this study should serve as guidelines for agencies to comprehend and understand a substantial amount of information regarding asphalt materials’ fatigue characterization so that it can be implemented as one of the quality control tests to assess the pavement design life.
20.	Rajczakowska, Magdalena, et al. (författare) Autogenous Self-Healing : A Better Solution for Concrete 2019 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 31:9 Tidskriftsartikel (refereegranskat)abstract Self-healing can be defined as the ability of a material to repair inner damage without any external intervention. In the case of concrete, the process can be autogenous, based on optimized mix composition, or autonomous, when using additionally incorporated capsules containing a healing agent and/or bacteria spores. The first process uses unhydrated cement particles as the healing material while the other utilizes a synthetic material or bacteria released into the crack from a broken capsule or activated through access of water and oxygen. The critical reviewing of both methods indicates that the autogenous self-healing is more efficient, more cost effective, safer, and easier to implement in full-scale applications. Nevertheless, a better understanding of the mechanism and factors affecting the effectiveness of the process is needed. The main weaknesses of the autonomous method were identified as loss of workability, worsened mechanical properties, low efficiency and low probability of the healing to occur, low survivability of the capsules and bacteria in harsh concrete environment, very high price, and lack of full-scale evaluation.
21.	Taghavi, Masoud, et al. (författare) Laboratory Study to Evaluate the In-Situ Use of Rejuvenator Seal Material to Restore In-Service Asphalt Pavement 2022 Ingår i: Journal of materials in civil engineering. - : ASCE-AMER SOC CIVIL ENGINEERS. - 0899-1561 .- 1943-5533. ; 34:10 Tidskriftsartikel (refereegranskat)abstract Rejuvenator seal material (RSM) is designed to revitalize an aged asphalt binder by spraying it on the surface of roads. It restores the mechanical properties of the existing pavement. This paper studied the effectiveness of RSMs containing cooking oil residue, motor oil residue, coal oil, solvent, and virgin or styrene-butadiene-styrene (SBS) modified 60/70 bitumen to improve the behavior of an in-service pavement. Three stages were followed to formulate RSMs. To achieve the effective oil, the penetration grade and softening point changes of rolling thin-film oven (RTFO) + pressure aging vessel (PAV) aged 60/70 bitumen mixing with different percentages of oils were studied. Then, the penetration depth of benzene, toluene, and xylene in hot mix asphalt (HMA) samples were measured to choose the most efficient solvent. Finally, the penetration depth of RSMs with various mixing ratios in HMA mixes was measured to determine the mix design and application values (g/m 2 ). RSM-A (5% COR + 5% MOR and 60/70 bitumen), RSM-B (5% COR + 5% CO and 60/70 bitumen), and RSM-C (5%COR + 5%CO and SBS modified 60/70 bitumen) were selected for further assessments. Other than the aforesaid RSMs, RejuvaSeal was used as a generic commercial substance. A British Pendulum Test was used to ensure sufficient skid resistance to reopen the traffic soon after distributing the RSMs. Dynamic shear rheometer and bending beam rheometer tests were used to investigate the theological properties of extracted bitumen from the upper 1.5 cm layer of the pavement with and without RSMs. Moreover, the fatigue behavior of rejuvenated asphalt mixtures was studied by the 4-point bending test. Based on the results, all RSMs had a positive effect on the softening of the aged bitumen. All RSMs regained the fatigue performance of the aged binder. However, they showed the reverse effect on the rutting resistance. RSM-C containing 5% COR + 5% CO and SBS modified 60/70 bitumen considerably modified the theological properties of the aged binder even better than those mixtures rejuvenated by RejuvaSeal.
22.	Varma, Remya, et al. (författare) Indices-Based Healing Quantification for Bituminous Materials 2021 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 33:11 Tidskriftsartikel (refereegranskat)abstract In the present study, three-point bending tests are carried out using single-edge notched beam specimens of bitumen and mastic to quantify healing. Experiments are conducted at a controlled displacement rate of 1 mm per minute at -15 degrees C. After the crack propagation, samples are given a rest period of 2 h at 10 degrees C to promote healing before retesting them. Two different analysis approaches appealing to linear elastic fracture mechanics and viscoelastic fracture mechanics are compared. In order to perform analysis based on viscoelastic fracture mechanics, the elastic-viscoelastic correspondence principle is used. The amount of healing after the rest period is quantified using various healing indices based on the recovery of stiffness, peak load, fracture toughness, fracture energy, and J-integral. From the analysis performed on bitumen and mastic samples, the study illustrates that the quantum of healing is different when comparing different healing indices. While the stiffness-based healing index demonstrated the healing ability of bitumen, other healing indices used in the study confirmed the higher healing potential of mastic. The healing based on critical value of J-integral shows a distinct difference in the healing of bitumen and mastic. The study emphasizes that the quantification of healing capacity when using different healing indices should be closely linked to its measured conditions.
23.	Younis, Adel, et al. (författare) Performance of Sewater-Mixed Recycled-Aggregate Concrete 2020 Ingår i: Journal of Materials in Civil Engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 32:1, s. 1-11 Tidskriftsartikel (refereegranskat)abstract The use of seawater and recycled coarse aggregate (RCA) in concrete mixtures leads to the production of a very sustainable concrete. The potential risk of steel reinforcement corrosion (due to chloride in the seawater) in such mixtures may be eliminated when considering plain concrete or noncorrosive reinforcement (e.g., fiber-reinforced polymer). This study investigated the fresh and hardened properties of a proposed green concrete mixed using seawater and recycled coarse aggregates. Two different concrete mixtures were studied, namely conventional concrete (Mix 1) and seawater-mixed concrete with RCA (Mix 2). Blast furnace slag was used as supplementary cementitious material at a 65% replacement level in both concrete mixtures. Fresh and hardened properties of the two concretes, including workability, strength gain, drying shrinkage, permeability, and microstructure, were characterized and compared. The results suggest that the use of seawater and RCA together has negative effects on concrete performance. Compared with the reference (Mix 1), Mix 2 concrete had approximately 5% lower density, 25% lower slump flow, 50% lower setting time, 33% lower strength gain, 10% higher drying shrinkage, 60% higher water absorption, and 100% higher charge passed (in rapid chloride permeability tests). Consequently, strategies to improve the performance of such concretes, such as a reduction in the water:cementitious materials ratio and the use of chemical admixtures, are suggested. These strategies, however, may somewhat reduce the green aspect of the proposed seawater-mixed concrete with RCA.
24.	Birgisson, Björn, et al. (författare) Microstructure and fracture in asphalt mixtures using a boundary element approach 2004 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 16:2, s. 116-121 Tidskriftsartikel (refereegranskat)abstract This paper describes the use of the displacement discontinuity boundary element method to model the microstructure of asphalt mixtures. The problem of indirect tension test (IDT) was used to demonstrate the application of the method in the modeling of the cracking behavior of asphalt mixtures. An IDT sample was modeled by three sets of displacement discontinuity boundary elements based on location and function: (1) on the periphery of the specimen, (2) inside the specimen to represent the aggregate structure, and (3) internal fracture path elements inside the aggregate structure. The mastic was modeled by a nonlinear failure law. The simulation of the cracking behavior of the IDT test with this method showed a good agreement with laboratory observations. The predicted stress-strain curves matched the experimental results for both vertical compressive stress and horizontal tensile stress. Crack patterns from these simulations were also similar to the patterns observed visually in the laboratory. In summary, explicit fracture modeling has shown promise as a tool for studying the crack growth and localization of asphalt mixtures.
25.	Karlsson, Robert, et al. (författare) Material-related aspects of asphalt recycling-state-of-the-art 2006 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 18:1, s. 81-92 Tidskriftsartikel (refereegranskat)abstract Current knowledge on material-related aspects of asphalt recycling with focus on findings from fundamental studies is summarized. By way of introduction, a general description of different types of asphalt recycling methods is given, after which a more detailed compilation of material-related knowledge is presented. Special attention is given to the binder rejuvenation process at asphalt recycling, that is the restoration of reclaimed binder properties. Studies concerning properties of recycled mixtures are also summarized.
26.	Kim, Sungho, et al. (författare) Porosity of the Dominant Aggregate Size Range to Evaluate Coarse Aggregate Structure of Asphalt Mixtures 2009 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 21:1, s. 32-39 Tidskriftsartikel (refereegranskat)abstract This paper presents the results from an evaluation of a new gradation-based framework developed for identifying and assessing the coarse aggregate structure of dense-graded mixtures for resistance to rutting. A theoretical packing-based analysis procedure was used to evaluate the coarse aggregate structure for hot mix asphalt mixtures. This procedure was applied to an extensive range of mixtures. A key feature of this new framework is the concept of the existence of a dominant aggregate size range (DASR). The porosity of the DASR is calculated based on an interaction diagram to evaluate the degree of particle-to-particle interaction of coarse aggregates between contiguous sieve sizes. In addition, an interaction diagram-based criteria for dense-graded Superpave mixtures are determined, as well as criteria for the porosity of the DASR. Based on the field and laboratory-based rutting performance of the mixtures evaluated in this paper, it was concluded that DASR along with the porosity of the DASR may provide a framework for evaluating the gradation of dense graded mixtures for their likely rutting potential.
27.	Lundstrom, Robert, et al. (författare) Linear viscoelastic and fatigue characteristics of styrene-butadiene-styrene modified asphalt mixtures 2004 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 16:6, s. 629-638 Tidskriftsartikel (refereegranskat)abstract Three styrene-butadiene-styrene coblock polymer modified asphalt concrete mixtures (70/100M5, 160/220M5, and 160/ 220M10) are characterized using complex modulus and fatigue testing. The compositions of the materials investigated are identical (aggregate, size distribution, binder, and void contents) and differ solely regarding binder characteristics. The modified binders are manufactured using two base bitumens (70/100 and 160/220) modified by a styrene-butadiene-styrene coblock polymer. The fatigue tests are carried out at three different temperatures (0, 10, and 20degreesC) using both stress- and strain-controlled modes. A continuum damage model is used to investigate its ability to characterize fatigue of polymer modified mixtures. The results indicate that the continuum damage model is suitable for characterizing the materials at the test conditions used (mode of loading, excitation amplitude, and testing temperature) in that visually similar material functions are obtained. Using statistical analysis, it was indicated that strain amplitude does not significantly influence the model parameters of the characteristic material functions. However, even though different loading conditions lead-to apparently similar material functions, the model parameter values were actually significantly affected by the testing temperature used. Predictions of fatigue path, including number of cycles to failure, based on the material functions indicate reasonable accuracy.
28.	Lundström, Robert, et al. (författare) Influence of asphalt mixture stiffness on fatigue failure 2004 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 16:6, s. 516-525 Tidskriftsartikel (refereegranskat)abstract This paper examines the question of an appropriate failure criterion for asphalt fatigue characterization. The results presented are based on cyclic fatigue tests and obtained from three mixtures containing different penetration grade bitumens from one and the same source. The mixtures are tested at 0, 10, and 20degreesC using uniaxial testing (tension/compression) on cylindrical samples. It is found that failure can be demonstrated by studying the evolution of the strain field using three parallel extensometers (separated by 120degrees around the specimen). The failure arises from coalescence of microcracks (damage localization). The decrease in stiffness at failure is related to mixture stiffness, where stiff materials (low temperature and/or mixtures containing low pen grade binder) show comparatively small decrease. A statistical approach based on fatigue tests carried out at different temperatures is suggested, an approach which uses stiffness degradation as a measure of critical fatigue stiffness. The advantage of such a failure criterion compared to the classical failure criterion (decrease in stiffness by 50%) for different temperatures is discussed. Using the proposed criterion, higher consistency in results is achieved compared to results obtained using the classical failure criterion.
29.	Masad, E., et al. (författare) Analytical derivation of permeability and numerical simulation of fluid flow in hot-mix asphalt 2004 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 16:5, s. 487-496 Tidskriftsartikel (refereegranskat)abstract Permeability is an important property that influences the performance of hot-mix asphalt (HMA). It is a function of compaction effort, and several properties of HMA such as asphalt content, and the shape and size distribution of aggregates. Due to the different laboratory and field methods for measuring permeability, and the interaction among the factors that influence its value, it would be difficult to develop an analytical equation that accurately relates permeability to all factors contributing to HMA permeability. This paper presents a simple equation for approximating the permeability of asphalt mixes. It utilizes the percent air voids and surface area of aggregates. The equation is empirical but it is derived based on the well-known Kozeny-Carman equation for calculating the permeability of granular materials. The developed equation was used successfully to fit permeability data collected from several studies that carried field and laboratory measurements of HMA permeability. A finite element model was developed to investigate the influence of the gradient of percent air voids in HMA on water flow patterns. The x-ray computed tomography was used to measure the percent air void gradients among sublayers of the asphalt mix. The permeability of these sublayers was calculated using the developed equation, and used as an input to the finite element model. The simulation results show that air void gradients in HMA encourage lateral flow in the horizontal direction and reduce the flow in the vertical direction.
30.	Tepfers, Ralejs, 1933, et al. (författare) Strengthening of Concrete Structures with Advanced Composite Materials - Prospects and problems 2004 Ingår i: Journal of Materials in Civil Engineering. - 1943-5533 .- 0899-1561. ; 16:5 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
31.	Täljsten, Björn (författare) Strengthening of beams by plate bonding 1997 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 9:4, s. 206-212 Tidskriftsartikel (refereegranskat)abstract At Luleå University of Technology, Sweden, research has been carried out in the area of plate bonding, i.e., the problems that can arise when concrete members need to be strengthened using epoxy-bonded plates. Both comprehensive experimental and theoretical work have been done. In this paper a derivation of the shear and peeling stresses in the adhesive layer of a beam with a strengthening plate bonded to its soffit and loaded with an arbitrary point load are presented. The results from both theory and finite-element analysis show that the stresses are very large at the end of the plate, but they quickly diminish as we move nearer the center of the beam. The magnitude of the stresses is influenced not only by the geometrical and material parameters of the beam, but also by the adhesive and the strengthening material.
32.	Masad, Eyad, et al. (författare) Analysis of Permeability and Fluid Flow in Asphalt Mixes 2004 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 16:5 Tidskriftsartikel (refereegranskat)
33.	Rogbeck, J, et al. (författare) Applications for PFBC residues 2000 Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 12:4, s. 294-301 Tidskriftsartikel (refereegranskat)abstract Pressurized fluidized bed combined-cycle (PFBC) ashes have proved favorable for utilization in a variety of applications. The Swedish Geotechnical institute has previously carried out comprehensive testing on ashes from ABB Carbon's pilot plant in 1988-1989, with complementary tests on ashes from the commercial plants in Vartan, Tidd, and Escatron. The scope of the tests was expanded in 1997-1998 to include fuel mixtures based on oil shale from ABB Carbon's test plant. While providing a historical and commercial perspective for the applications for PFBC residues, the focus of this paper is upon the result of investigations performed on ashes from oil shale fuel combinations.
34.	Shi, Pan, et al. (författare) Shock Wave-Induced Dynamic Mechanical Behavior of Calcium Silicate Aluminate Hydrate at the Molecular Scale 2023 Ingår i: Journal of materials in civil engineering. - : American Society of Civil Engineers (ASCE). - 0899-1561 .- 1943-5533. ; 35:8 Tidskriftsartikel (refereegranskat)
35.	Varma, Remya, et al. (författare) On Indices Based Healing Quantification for Bituminous Materials Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. Tidskriftsartikel (refereegranskat)abstract In the present study, three-point bending tests are carried out using single-edge notched beam specimens of bitumen and mastic to quantify healing. Experiments are conducted at a controlled displacement rate of 1 mm per minute at -15 ℃. After the crack propagation, samples are given a rest period of 2 hours at 10 ℃ to promote healing before re-testing them. Two different analysis approaches appealing to linear elastic fracture mechanics and viscoelastic fracture mechanics are compared. In order to perform analysis based on viscoelastic fracture mechanics, the elastic-viscoelastic correspondence principle is used. The amount of healing after the rest period is quantified using various healing indices based on the recovery of stiffness, peak load, fracture toughness, fracture energy, and J-integral. From the analysis performed on bitumen and mastic samples, the study illustrates that the quantum of healing is different when comparing different healing indices. While the stiffness-based healing index demonstrated the healing ability of bitumen, other healing indices used in the study confirmed the higher healing potential of mastic. The healing based on critical value of J-integral shows a distinct difference in the healing of bitumen and mastic. The study emphasizes that the quantification of healing capacity when using different healing indices should be closely linked to its measured conditions.
36.	Wong, Dawn Yun-Cheng, 1992, et al. (författare) Maturity-Based Method of Early-Strength Characterization of Rapid-Setting Cements 2024 Ingår i: Journal of Materials in Civil Engineering. - 1943-5533 .- 0899-1561. ; 36:9 Tidskriftsartikel (refereegranskat)abstract The expedient repair of damaged airfield pavements is important to eliminate long closure periods. Rapid-setting cement (RSC) is promising for achieving target strength in a much shorter duration (4-6 h) compared to conventional repair methods. However, when the objective is to reopen the pavement within 1-2 h, there is a lack of methods to quantify the development of mechanical properties during the first few hours. In this study, a simplified maturity method is proposed to monitor the very early-strength development of two commercially available RSC mixes with different strength development mechanisms. The results were validated using hydration chemistry data from scanning electron microscope (SEM) experiments and ultrasonic pulse velocity (UPV) tests. The experimental results show that such a maturity-based approach is effective and robust in characterizing the early-strength development of the two RSC mixes despite variations in ambient temperature conditions.
37.	Janz, Mårten (författare) Technique for measuring moisture storage capacity at high moisture levels 2001 Ingår i: Journal of Materials in Civil Engineering. - 0899-1561. ; 13:5, s. 364-370 Tidskriftsartikel (refereegranskat)abstract Knowledge of moisture storage capacity above the hygroscopic range is essential when calculating moisture, especially when different materials are to be connected. Generally, the storage capacity is represented by water retention curves, in which suction is plotted against the moisture content. In a number of laboratories in Europe and North America, the pressure plate and pressure membrane techniques are used to measure water retention curves. There are, however, various ways of carrying out such measurements. This paper compares two different methods of presaturating the specimens before testing, namely capillary and vacuum saturation. It also examines the effect of different beddings between the specimen and the ceramic plate. It is shown, as expected, that capillary and vacuum saturated specimens give differential results. Absorption tests clearly show that, for some materials, capillary saturation is a vague concept. For this reason, vacuum saturation is generally to be preferred. In the test with different beddings, no significant differences were found.

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