Journal of Materials in Civil Engineering

Limited studies investigated the effect of recycled polymers obtained from the paint industry on concrete bond stress-slip with embedded steel bars, including whether such behavior would be similar to that imparted by virgin polymeric latexes. Around 50 concrete mixtures containing different vinyl acrylic-based polymer concentrations are tested by direct bond and beam-end methods. Test results have shown that the concrete-bar interfacial bond stresses occurring in the elastic region substantially improved with recycled and virgin polymers. At a similar polymer-to-cement ratio, concrete incorporating recycled polymers exhibited improved bond properties than mixtures prepared with virgin ones. This was indirectly related to the pigment and extender powders in the waste latex paints, thus reducing porosity and improving denseness of cement paste that strengthen the transition zone adjacent to reinforcing bars. The effect of reducing the water-to-cement ratio while adding superplasticizer to compensate the loss in workability and compressive strength was found efficient to increase the ultimate bond strength.

This paper investigates the applicability of using optimized self-consolidating rubberized concrete (SCRC) and vibrated rubberized concrete (VRC) mixtures in structural applications. The curvature ductility, ultimate flexural strength, and cracking characteristics of different SCRC and VRC mixtures were tested using large-scale reinforced concrete beams. The variables were crumb rubber (CR) percentage (0–50% by volume of sand), different binder contents ($500–550\mathrm{kg}/{\mathrm{m}}^3$), inclusion of metakaolin (MK), use of air entrainment, and concrete type. The performance of some design codes were evaluated in predicting the cracking moment and crack widths of the tested beams. The results indicated that although the flexural capacity of the tested beams decreased with the addition of CR, adding CR improved the beams’ curvature ductility and reduced its self-weight. Adding CR into concrete also appeared to limit the flexural crack widths but with a slightly higher number of cracks compared to beams without CR. In general, the obtained results from the present work indicate promising potential for SCRC and VRC use in structural applications.

An experimental investigation on corroded composite push-out specimens was performed to investigate the behavior of stud shear connectors subjected to fatigue loading. A total of 14 standard push-out specimens were tested under static and fatigue loading. A static push-out test was performed to obtain the ultimate strengths for reference. The expected corrosion rate of test specimens ranged from 0 to 50%. The main purpose of these tests was to determine the fatigue life and the reduction effect of the fatigue life caused by the corrosion. The effect of corrosion on the fatigue crack, load-slip curves, and failure modes were also studied. The test results were also compared with current Eurocode design predictions, which are only for a specimen without corrosion. The suitability of the Eurocode design equation for fatigue life of corroded composite push-out specimens was evaluated.

Conventional asphalt concrete is relatively low conductive. This paper focus on the improvement of thermal properties of asphalt mixtures using conductive fillers, and investigating the conduction performance by two-dimensional (2D) simulation. Also, the microstructure of asphalt mixture was analyzed with extremely high magnification to observe the distribution of conductive fillers in the mixture. Indirect tensile (IDT) strength was additionally investigated. Different asphalt mixtures used in this study was modified with milled carbon fiber, chopped carbon fiber, and graphite powder. The study also evaluated the effect of mixed fillers combined carbon fiber with varying admixtures of graphite contents. The thermal properties of modified asphalt mixtures were measured and calculated to evaluate their conduction effects to obtain the appropriate kind and quantity of carbon fibers and graphite. Based on the results of thermal properties of the asphalt mixtures, the 2D simulation was performed on a typical pavement design using the finite element method to comprehend the conduction performance taking place in pavement structure. The IDT test was conducted to compare the IDT strength of asphalt mixture modified with carbon fiber and others. Microstructure analysis was conducted on scanning election microscopy (SEM) images of the fractured surface of specimens. Thermal testing and analysis results indicated that carbon fibers and graphite basically increase the thermal properties of asphalt mixtures. The combination of mixed fillers provided certain advantages over single graphite or carbon fiber filler. The simulation results presented the reasonable and reliable heat conduction correlated with each conductive filler. The IDT test inferred that the tensile strength of asphalt mixture was enhanced with an addition of certain amounts of the chopped carbon fiber. According to microanalysis, graphite particles show the formation of conductive clusters throughout the asphalt mixture, whereas carbon fibers show a long-range connecting effect.

This paper presents the results from a laboratory study in which the influence of metal-free tire-derived aggregates (TDA) on the performance of ballast materials was evaluated. The use of waste TDA mixed with ballast of the same gradation is considered as an economic and environmentally friendly solution to reduce ballast degradation, which in turn increases the service life of the railway track. To evaluate the behavior of ballast–TDA mixture, a series of ballast physical tests incorporating different percentages of TDA was accomplished and then the durability of specimens was investigated. The results show considerable improvement of physical performance, especially in abrasive behavior. Moreover, the effects of TDA on ballast mechanical behavior including the shear strength and the deformation performance were determined, using the direct shear test and a ballast box test. Overall, an optimal value of 10% by weight is proposed for practical use at which the particle breakage and the long-term settlement of ballast will be reduced by 47 and 6%, respectively, while the ballast shear strength will be slightly reduced.

Reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) have been increasingly used in asphalt mixtures. The use of RAP and RAS in asphalt mixtures not only reduces the consumption of virgin materials, conserves energy, and protects the environment but also improves the rutting resistance of asphalt pavements. However, as more recycled materials are used in asphalt mixtures, there is increasing concern over their potential negative effects on the mix cracking resistance. To improve the cracking resistance of asphalt mixtures with high RAP/RAS contents, one of the approaches considered is using recycling agents to potentially restore performance properties of the aged binder. This project was conducted to evaluate the effect of a recycling agent (RA), known as Hydrogreen, on the long-term field performance of high RAP and RAS mixes. The field study consisted of three test sections, each constructed by placing a dense-graded surface lift at a depth of 4.5 cm (1.75 in.) on SR 7 near Harrisonville, Missouri, in August 2013. The three mixes placed in the three test sections included: (1) a control mix containing 30% RAP using an SBS-modified PG 70-22 binder with no RA; (2) a 40% RAP mix using the same PG 70-22 binder with RA; and (3) a 25% RAP and 5% RAS mix using a neat PG 64-22 with RA. This paper presents data collected during the construction of the test sections, laboratory performance testing results, and early field performance. The research results showed that the recycling agent could be used in the 40% RAP and 25% RAP and 5% RAS mixes to achieve similar construction quality, laboratory performance, and early field performance to the 30% RAP control mix. As these sections are still in service, it is recommended that they continue to be monitored in order to evaluate their long-term performance.

Experiments were conducted to assess the effects of using fiber-reinforced polymer (FRP) wraps, with fibers oriented in the hoop direction, for rehabilitating corrosion-damaged columns. This paper reports findings related to the freeze-thaw durability of concrete specimens with round and square cross sections, wrapped with glass and carbon FRP, after they are subjected to an internal expansive force similar to that generated by corroding steel. The results of the experiment indicate that freeze-thaw cycles have no statistically significant effect on the compressive strength of glass- and carbon-wrapped specimens. Freeze-thaw conditioning generally reduced the longitudinal failure strain of wrapped specimens. The square wrapped specimens had lower compressive strength compared to the round specimens, even though the cross-sectional area of the square prisms was higher than that of the round cylinders. This is because of the reduced confinement provided by the wraps for square cross sections and stress concentrations that develop at the corners. Wrapped square prisms always failed by rupture of the wrap at a corner. A reduction of approximately 30 to 40% in failure stress was noted between wrapped specimens with round and square cross sections, respectively.

The smart cement behavior with 0.3% sodium metasilicate (SMS) at 80°C (176°F) under two different environments was investigated in this study. The smart cement was made using the class H oil well cement and 0.1% conductive filler to make it a bulk chemo-piezoresistive material with highly sensing property. The smart cement was cured in air and also submerged in water-saturated sand at 80°C up to 28 days. The smart cement initial resistivity (${\rho }_o$) decreased from 0.97 to $0.87\mathrm{\Omega }·\mathrm{m}$ with 0.3% SMS, a 10% decrease. Similarly the minimum resistivity (${\rho }_{\min }$) decreased from 0.81 to $0.72\mathrm{\Omega }·\mathrm{m}$ with 0.3% SMS, an 11% decrease, which is an indication of the chemo-resistivity of the smart cement. The resistivity changes were higher than the unit weight changes in the smart material. The resistivity of the smart material oven cured in saturated sand at 80°C was 55 to 75% less than the resistivity of the material cured at 80°C after curing for one, seven, and 28 days. The material resistivity with 0.3% SMS cured in both conditions were about 25–55% less than the smart cement only. The resistivity with curing time under different curing conditions was modeled using a nonlinear curing model, and the prediction agreed well with experimental results. Also, a nonlinear power relationship was used to relate the resistivity to the weight change in the cement. The smart cement cured at high temperature (80°C) showed piezoresistive response under applied stress. For the smart cement the piezoresistivity at compressive strength changed from 245 to 475%. With 0.3% SMS the chemo-piezoresistivity at compressive strength varied from 160 to 345% based on the curing time and curing environment, which is an indication of the chemo-piezoresistivity of the smart cement. The smart cement cured in saturated sand showed higher piezoresistivity, about 15–25% more compared to the dry curing. Since the failure strain for the smart cement was only 0.2%, the piezoresistivity at peak compressive stress of the smart cement has been enhanced by more than 900 times, making it highly sensing. The compressive stress resistivity constitutive model predicated the material behavior very well. Also, a hyperbolic model was used to predict correlation between materials properties and also changes with curing time investigated in this study.

Global warming and climate change have increased the frequency of heavy precipitation. Heavy rainfall results in a large amount of water entering roadways within a short time period. Water remains in the pavement system for a certain time period, reduces strengths and moduli of granular bases and subgrades, and induces pavement distresses. Geotextiles are commonly used in roadways for drainage purposes, which require soil saturation. However, soil saturation does not always exist in roadways to enable gravity drainage of water by conventional geotextiles. Wicking geotextile, a new type of woven geotextile, was recently introduced to the market to remove moisture from unsaturated soils. The wicking geotextile includes special hydrophilic and hygroscopic 4 deep groove fibers with multichannel cross sections, which can induce high capillary force to wick water out of moist soil without saturation of soil. The ability and rate of this geotextile to remove water from moist soil depends on several factors, including temperature and relative humidity. In this study, a series of laboratory tests under controlled temperature and relative humidity were conducted to quantify the water removal rate of the wicking geotextile. A half length of the wicking geotextile was submerged in water tanks, and the other half was hung outside of the tanks. The water wicked from the tank into the geotextile evaporated into the air. Such tests were conducted under 12 different test conditions (i.e., different temperatures and relative humidities). Test results demonstrated that the wicking geotextile could remove water from the water tank at a certain rate. Three commonly used methods available in the literature were adopted to quantify the water removal rate of the wicking geotextile based on vapor pressure, temperature, and relative humidity. A new concept of equivalent water evaporation length of a wicking geotextile is proposed in this study. It should be pointed out that the tests presented in this paper aimed to determine the maximum water removal capacity of the geotextile given sufficient water supply.

Numerical simulation for asphalt concrete using the finite-element (FE) method has been widely explored during the last few decades. However, the FE model reconstructions for asphalt concrete samples are mainly limited to the X-ray imaging approach. Although some computer-generated FE models have been used in previous studies, related work is still at a very preliminary stage. Different from FE modeling for asphalt concrete, discrete element (DE) modeling has been well developed using user defined aggregate models with the aid of commercial software. This study aims to bridge the DE models with FE models for asphalt concrete by using virtual cross-sectional imaging and indirect cubic element meshing. In the first approach, virtual cross-sectional imaging is conducted to identify the areas occupied by aggregate particles and air voids. These virtual cross-sectional images are afterward stacked to form three-dimensional (3D) solid models. Then, the 3D solid models are triangularly meshed and imported into the FE simulation software, ABAQUS. By this means, an FE model with tetrahedral elements is reconstructed. In the second approach, arranged spheres are generated to fill the entire sample first. The circumscribed cubes of the spheres are found and regarded as the cubic elements in FE models. An input file containing elemental and nodal information is directly written by PFC3D using user-written functions. Then the input file is imported into ABAQUS, and an FE model with hexahedral elements is reconstructed. This study provides a new and effective approach for FE model reconstruction of asphalt concrete with user defined aggregate and air void models. Additionally, the advantages and limitations of the two approaches are discussed.

The corrosion of steel caused by chloride ions is considered to be the main durability problem of reinforced concrete structures. This paper investigates the total chloride ion content, free chloride concentration in expressed pore solution, Friedel’s salt content, and porosity of portland cement (PC) and PC/fly ash (FA) combination pastes after 7 days of water curing followed by 28 or 150 days immersion in water or 0.3, 0.7, 1.0, and $2.0\mathrm{mol}/\mathrm{L}$ sodium chloride solutions. Results showed that the chloride ion binding capacities of the pastes increased with increase of free chloride ion concentration. The relationship between bound and free chloride ion contents could be described by Langmuir’s equation. The addition of fly ash decreased the bound chloride content and showed negative influences on Friedel’s salt formation due to low activity. Porosity of cement paste decreased as the concentration of soaking chloride ion increased, and was inversely proportional to the amount of Friedel’s salt formed.

Asphalt binder adaptation in cold and spacious areas such as Alaska is critical because of varying climates and seasonal extreme conditions. To fully address the binder selection issues in Alaska, this paper presents a study that conducted analysis based on a long-term pavement performance (LTPP) database to reveal the climatic effects on binder selection, followed by evaluation of the laboratory and field performance of hot mix asphalt (HMA) containing neat binder and several currently used modified binders in Alaska. It was found that the recommended high performance grading (PG) grades for the entire Alaska are equal to or lower than 52°C, whereas the low grades in more than 76% of the recorded weather stations in Alaska are recommended to be lower than $-28°\mathrm{C}$. Laboratory testing results showed that HMA with high-end modified binders expressed higher rutting resistance than that containing the neat binder PG 52-28, and HMA with the neat binder displayed the lowest resistance to low-temperature cracking compared to modified binders. Field surveys suggested that increasing high temperature grade would improve rutting resistance in Alaska Department of Transportation and Public Facilities (ADOT&PF)’s Central Region, although there was not enough evidence to draw any conclusion on modified binders’ low-temperature performance in the Northern Region. It is recommended to keep using high-end modified binders in the Central Region and extend the low PG grade to $-46$ and/or $-52$ in trial projects in the Northern Region. In addition, more field projects covering different low-end modified binder grades in the Northern Region should be developed for better evaluation of low-temperature performance in that area. Furthermore, a systematic study of highly modified binders through both laboratory tests and field project monitoring is needed to provide more performance data and information for ADOT&PF to fully develop specifications of modified binders to better address the extremely climatic conditions in Alaska.

In this research work, based on the permanent strain mechanisms, the behavior of asphalt mixture under different loading conditions was examined in a cyclic compression creep test. This research study was conducted with three loading patterns at three pulse durations and stress levels. The results show the following: (1) the permanent strain mechanisms are strongly affected by stress level, pulse duration, loading patterns, and their interactions; (2) the rate of change in permanent strain from stress at a low stress level is significantly higher than that at a high stress level; (3) asphalt specimens with higher initial strain will show a lower rate of rutting progression as the number of load applications increases; (4) at a pulse duration corresponding to low speed, the asphalt specimen shows permanent strain over a shorter period of time, but at high speed this condition is dependent on stress level; (5) cumulative permanent strain is not linearly proportional to stress level for all loading conditions; and (6) at a low stress level, permanent strain of asphalt specimens will occur over a longer time period than that at a high stress level.

Geopolymer concrete is an innovative construction material that utilizes industrial by-product waste materials to form a cement replacement for concrete manufacture. In order to simulate the behavior of reinforced concrete at all load levels, an understanding of the bond between the reinforcement and the concrete is required. That is, at the serviceability limit state, the bond between the reinforcement and the concrete controls the formation of cracks, crack widening, and tension stiffening. Similarly, adequate bond between the reinforcement and the concrete is required at the ultimate limit state to ensure the full capacity of the reinforcement is obtained. Over time, the bond between the reinforcement and concrete can deteriorate due to corrosion, thus impacting the overall performance of a structure. This paper presents a wide-ranging study of the bond between reinforcement and geopolymer concrete including an investigation of the influence of corrosion. This study involved 102 pull-out test specimens covering a range of parameters including bar diameter, concrete cover-to-diameter ratio, compressive strength, and level of corrosion. Significantly, this study shows that the bond between reinforcement and geopolymer concrete is stronger than that between reinforcement and ordinary portland cement.

This work evaluates best practices for managing the corrosive effect of magnesium-chloride-based deicers on the metallic components of equipment fleets. The first part of this study evaluates the effectiveness of salt remover for washing bare metals. A dip-dry test was employed to simulate the field conditions. Carbon steel (C1010), aluminum alloy (Al1100), and stainless steel (SS304L) were used in the test program to evaluate the use of water, soapy water, and a commercial salt remover in washing practices. The corrosion behavior of metals was studied using linear polarization and electrochemical impedance spectroscopy measurements. Digital photos and scanning electron microscopy revealed the surface morphology of corrosion coupons. The salt remover could significantly enhance the corrosion resistance of carbon steel and stainless steel in a 30%-by-weight ${\mathrm{MgCl}}_2$ solution, but not that of the aluminum alloy. Further investigation focused on the evaluation of an innovative sugar beet by-product for use as a deicer additive. A modified dip-dry test was employed to simulate the field conditions. Bare and coated C1010 samples were used to evaluate the potential anticorrosion benefits of this green deicer additive. The corrosion behavior of the samples was characterized using electrochemical impedance spectroscopy. The use of sugar beet by-product can enhance the corrosion resistance of carbon steel and the mechanism of protection is the formation of a temporary protective layer on the metallic surface.

Phosphogypsum (PG) is a by-product of the phosphoric acid fertilizer industries that has possible applications in paving when stabilized with cement or lime. This study’s aim is to compare the mechanical performance of the hemi-hydrate (HH) and dihydrate (DH) mixes with tropical soil, lime, and cement. The results of physical, mechanical, and mineralogical tests are presented, which demonstrate that the use of HH in cement and lime mixes reduces the swelling of this material compared to the use of DH; in addition, HH provides better mechanical behavior. These findings indicate that DH has limited application in pavement construction, but when converted into HH and mixed with tropical soil or chemical stabilizers, its alternative uses are possible, and more content (approximately 90%) of this material can be used.

The objective of this study was to evaluate the self-healing effectiveness of urea-formaldehyde microcapsules with calcium nitrate as a healing agent in cement mortar. Calcium nitrate was selected as a healing agent because of its ability to react with available unhydrated cement particles in crack surfaces contributing to the formation of new hydration products that may potentially heal the crack. Self-healing capability of cement mortar with different microcapsule contents was evaluated under dry and wet healing conditions. Cracks ranging from 27.0 to 386.5 μm on average were created by three-point bending and indirect tensile tests. Cracks were observed by light microscopy over a 28-day healing period. Analysis of captured images showed signs of healing in the form of small crystallike features on the edge of the cracks on water-cured specimens after 7 days of healing. Furthermore, an improvement in self-healing efficiency was reported in specimens with microcapsule contents of 0.85 and 1.0% compared to the control after 14 days of the healing period. Environmental scanning electron microscopy (ESEM) coupled with energy dispersive spectroscopy (EDS) was utilized to investigate the morphology and chemical nature of the healing products. Crystallike and gellike healing products were found with the majority being crystallike. Crystallike healing products were likely calcium carbonate in the form of calcite crystals, whereas gellike healing product’s chemical nature was presumably calcium silicate hydrate (CSH).

Due to the ever-increasing demand for electricity, generation of fly ash in large quantities has become a problem throughout the world. The utilization of fly ash in rail and road embankments in earthquake-prone areas requires thorough understanding of its dynamic strength characteristics. A series of resonant column and cyclic triaxial tests have been carried out on fly ash to investigate the influence of various factors on its maximum dynamic shear modulus ($G_{\text{max}}$) and dynamic damping ($D_s$). Correlations for predicting $G_{\text{max}}$ and $D_s$ for fly ash have been proposed. The fly ash is found to be far more liquefiable than sand. The particle-size distribution and low unit weight play a vital role in the determination of cyclic strengths. The dynamic shear damping is found to be very much influenced by the confining pressure and induced strain, but independent of the relative density of the fly ash. The damping of sand is found to be always more than the damping of the fly ash irrespective of the confining pressure.

In the United States alone, the cost to repair structures damaged by expansive soils has been estimated to be twice the combined damages of natural disasters. Despite the widespread occurrence of these soils, the damage caused by the presence of expansive soils is regularly overlooked because it might take years of distress exposure before extensive damage to infrastructure can be observed. To predict the heave and swelling pressure an expansive soil will experience in the field, it is standard practice to subject a remolded specimen to a wetting process at a particular net normal stress. This practice does not capture the behavior of expansive soils in the field and therefore, it is necessary to assess the long-term environmental effects on their behavior. In this study, an assessment of the effect of multiple wetting/drying cycles on the volume change behavior of two naturally occurring expansive soils was performed. The soils were remolded at different initial compacted conditions, loaded to different net normal stresses, wetted to nearly 100% saturation and then subjected to full drying. In general, it was observed that after four cycles, the swelling or collapse strain and the swell pressure reached equilibrium. When the applied stress exceeded 25% of the swell pressure, both soils exhibited an increase in collapse potential from the previous wetting cycle. However, when the applied stress was less than 25% of the swell pressure, both soils exhibited an increase in swell potential from the previous cycle.

Effects of silicate modulus (Ms) of an activator solution and the matrix components of alkali-activated slag cement (AASC) on the flexural parameters of AASC mortars were investigated under static and low-velocity impact loadings. AASC mixtures in two different Ms (${\mathrm{SiO}}_2/{\mathrm{Na}}_2\mathrm{O}$) ratios were prepared by the partial replacement of ground granulated blast-furnace slag (GGBFS) with fly ash (FA), metakaolin (MK), and silica fume (SF). Impact load was generated by a free-fall of a hammer onto the simply supported notched beams from different heights. Test results showed that SF-incorporating AASC had similar impact resistance to the control AASC mixture at all tested velocities while the MK-incorporating AASC had significantly lower impact resistance with an Ms ratio of 0.8. The increase of Ms ratio had a profound effect only in the MK series. The dynamic increase factors (DIF) in AASC mixtures increased with impact velocity. Dynamic increase factors were found to be higher in the AASC mixtures having porous and fissured microstructures than the well-packed and compact ones. AASC mixtures having similar quasi-static flexural performance to a portland cement mortar presented higher low-velocity impact resistance, fracture energy, and ductility index values under impact conditions.

This study evaluates the impact resistance and mechanical properties of a number of developed self-consolidating rubberized concrete (SCRC) mixtures reinforced with steel fibers (SFs). In this research, SFs were used to compensate for the reduction in tensile and flexural strength that resulted from adding high volumes of crumb rubber (CR). SFs were also used to exploit the beneficial interaction between SFs and CR to develop low-density concrete with higher impact resistance. The experimental variables were different replacement levels of fine aggregate volume by CR (0–40%), binder content ($550{–600\mathrm{kg}/\mathrm{m}}^3$), SF volume fractions (0, 0.35, 0.5, 0.75, and 1%), and size of SFs. Tests included fresh properties, compressive strength, splitting tensile strength (STS), flexural strength (FS), and impact loading (drop-weight on cylindrical specimens and flexural impact loading on small-scale beams). The results indicated that adding CR to concrete improved the impact energy absorption and ductility, whereas the mechanical properties decreased as the percentage of CR increased. Using SFs can greatly increase the impact resistance of SCRC and compensate for the reduction in STS and FS that resulted from the addition of CR. However, the high blockage in the L-box test limited the possible combination of SFs and CR in SCRC mixtures. Since passing ability was not a factor in the development of vibrated rubberized concrete (VRC), it was possible to combine higher volumes of CR and SFs safely in VRC, achieving more reductions in self-weight and improvements in the STS, FS, ductility, and impact resistance.

The linear amplitude sweep (LAS) test has been proposed for fatigue specifications of asphalt binders. Recently, a newly developed fatigue failure definition and energy-based failure criterion have been proposed for improving the LAS procedure and data interpreting; however, these improvements only affect LAS data conducted at a constant temperature. This paper, therefore, discusses the loading temperature effects on LAS-based binder fatigue, damage evolution, and final fatigue failure occurrence. Experimental results indicate that both damage characteristic curves (DCCs) and the failure criterion derived from the simplified-viscoelastic continuum damage (S-VECD) model are strongly affected by the testing temperature. However, the temperature shift factors determined from the dynamic shear modulus testing within the linear viscoelastic domain have been proven to be effective in eliminating the temperature influence for both fatigue DCCs and the failure criterion. The validation on binder phase demonstrates that the time-temperature superposition principle (TTSP) shift factor is only a function of temperature and is independent of strain level. TTSP application on both undamaged and damaged material behaviors is able to greatly improve the testing efficiency of the LAS-based binder fatigue characterization.

This paper presents results of experimental research on the impact of different types of lightweight aggregates and supplementary cementitious material (fly ash and metakaolin), on basic physical and mechanical properties of structural lightweight aggregate concrete (LWAC). The used aggregates are: lightweight aggregate obtained by firing waste materials (mixture of stone sludge, paper sludge, and fly ash) and expanded recycled glass. The results showed that it is possible to obtain structural LWAC with both types of lightweight aggregates even with substitution of cement with fly ash up to 45% (by mass). LWAC with high amount of active mineral admixtures and low water-binder ratio achieved higher compressive strength and specific strength compared to LWAC made only with portland cement. Comparison of static ($E_c$) and dynamic ($E_d$) modulus of elasticity showed that, for everyday engineering practice, static modulus of elasticity of LWAC can be determined using proposed expression $E_c=0.65·E_d$ with high reliability.