Showing papers on "Durability published in 2017"
TL;DR: The use of fly ash in concrete dates back to the late 20th century and its advantages and disadvantages had been widely researched as mentioned in this paper, however, the level of replacement is still limited to a maximum of 35% of cement by mass.
417 citations
TL;DR: In this paper, an extensive literature review has been done to address relationship between concrete electrical resistivity and its certain durability characteristics These durability characteristics include chloride diffusivity and corrosion of reinforcement as these have major influence on concrete degradation process Overall, there exists an inverse or direct proportional correlation between these parameters Evaluated results, from measuring the concrete electrical resistor, can also be used as a great indicator to identify early age characteristics of fresh concrete and for evaluation of its properties, determination of moisture content, connectivity of the micropores, and even condition assessment of in-service structures
Abstract: Degradation processes in reinforced concrete structures that affect durability are partially controlled by transport of aggressive ions through the concrete microstructure Ions are charged and the ability of concrete to hold out against transfer of ions greatly relies on its electrical resistivity Hence, a connection could be expected between electrical resistivity of concrete and the deterioration processes such as increase in permeability and corrosion of embedded steel Through this paper, an extensive literature review has been done to address relationship between concrete electrical resistivity and its certain durability characteristics These durability characteristics include chloride diffusivity and corrosion of reinforcement as these have major influence on concrete degradation process Overall, there exists an inverse or direct proportional correlation between these parameters Evaluated results, from measuring the concrete electrical resistivity, can also be used as a great indicator to identify early age characteristics of fresh concrete and for evaluation of its properties, determination of moisture content, connectivity of the micropores, and even condition assessment of in-service structures This paper also reviews and assesses research concerning the influential parameters such as environmental conditions and presence of steel rebar and cracks on measuring electrical resistivity of concrete Moreover, concrete resistivity concept, application, and its various measurement techniques are introduced
197 citations
TL;DR: A review of the effect of surface treatments on mechanical properties and durability concrete, and the durability of treatment materials themselves is presented in this paper, where several common surface treatments are reviewed, including acrylic coating, polyurethane coating, epoxy coating, silanes, siloxanes sodium silicate, and nano-SiO2.
138 citations
TL;DR: In this paper, the authors investigated the feasibility of applying ductile engineered cementitious composites (ECC) as an alternative to conventional concrete in hydraulic structures to improve their durability performance.
131 citations
TL;DR: A facile, cost-effective, and scalable method for manufacturing E-skin devices with bionic hierarchical microstructure and microcracks, which exhibit high sensitivity and excellent durability and a series of studies on the airflow detection and the noncontact speech recognition.
Abstract: Electronic skin (E-skin), a popular research topic at present, has achieved significant progress in a variety of sophisticated applications. However, the poor sensitivity and stability severely limit the development of its application. Here, we present a facile, cost-effective, and scalable method for manufacturing E-skin devices with bionic hierarchical microstructure and microcracks. Our devices exhibit high sensitivity (10 kPa–1) and excellent durability (10 000 cycles). The synergistic enhancement mechanism of the hierarchical microstructure and the microcracks on the conductive layers was discovered. Moreover, we carried out a series of studies on the airflow detection and the noncontact speech recognition.
119 citations
TL;DR: In this article, the authors investigated the durability of a low-calcium fly ash based geopolymer concrete (GPC) mix in a saline lake environment and found that the particular GPC mix design was more vulnerable to carbonation and the deterioration effects due to chloride and sulphate ingress in GPC were higher than OPC concrete after 6 years of exposure.
114 citations
TL;DR: In this article, a quantitative investigation was conducted to evaluate the effects of different surface modification methods on the surfaces' mechanical durability and the collective results showed that the low surface energy materials had significant effects on the surface roughness, which would then play an important role in the durability of these rough surfaces.
85 citations
TL;DR: In this paper, the carbonation depth of AAS concrete was investigated by using a CO2 gas chamber for two cycles of 14 and 28 days, and then the resulting depth of carbonation was measured and analyzed.
75 citations
TL;DR: In an attempt to study the effect of heat treatment on hygroscopicity and durability of wood, Poplar (Populus spp.) wood was thermally modified using five different temperatures between 170 degrees and 170 degrees as discussed by the authors.
73 citations
TL;DR: In this article, the diameter of glass fiber-reinforced polymer (GFRP) bars used as internal reinforcement in concrete structures is considered as a factor influencing bar durability.
Abstract: Current standards do not consider the diameter of glass fiber-reinforced polymer (GFRP) bars used as internal reinforcement in concrete structures to be a factor influencing bar durability....
72 citations
TL;DR: In this paper, the authors examined the bond durability of GFRP bars embedded in different types of concrete (Normal, self-compacting, light weight, and high strength) exposed to aggressive environments, namely, sea water, alkaline, and acid.
TL;DR: In this paper, the authors presented the bond durability of glass fiber-reinforced polymer (GFRP) bars to fiber reinforced concrete (FRC) exposed to saline solutions.
TL;DR: In this paper, the possibilities for creating durable high performance foam concrete by applying intensive mixing technology and using modifying micro admixtures are discussed, such as strength, density, water absorption, carbonization and frost resistance.
TL;DR: The results of this study suggest that universal adhesives modify the interfacial characteristics of a wide range of substrates and create a consistent surface, but the bond durability of universal adhesive to various substrates differs depending on the type of substrate and the adhesive.
Abstract: Clinical Relevance Clinicians should follow the procedures associated with universal adhesives to modify the interfacial characteristics carefully and pay attention to the factors that contribute to the bond durability of universal adhesives with various substrates; in particular, clinicians should be aware of their chemical bonding potential.
TL;DR: In this paper, a test method is presented which allows determination of realistic diffusion coefficients for chloride ions in concrete under compressive or tensile stress, and compared results from five different laboratories showed that the combination of mechanical and environmental loads may be much more severe than a single environmental load without mechanical loading.
Abstract: At present several methods are available to predict the durability of reinforced concrete structures. In most cases, one dominant deterioration process such as carbonation or chloride penetration is taken into consideration. Experimental results as well as observations in practice show that this is not a realistic and certainly not a conservative approach. In order to test more realistically, RILEM TC 246-TDC, founded in 2011, has developed a method to determine the durability of concrete exposed to the combined action of chloride penetration and mechanical load. In this report, a test method is presented which allows determination of realistic diffusion coefficients for chloride ions in concrete under compressive or tensile stress. Comparative test results from five different laboratories showed that the combination of mechanical and environmental loads may be much more severe than a single environmental load without mechanical loading. Modelling and probabilistic analysis also showed that the obvious synergetic effects cannot be neglected in realistic service life prediction.
TL;DR: In this article, the influence of freezing-thawing and ageing on mechanical properties and thermal characteristics of conductive asphalt concrete (CAC) were experimentally investigated by Thermal Constants Analyzer.
TL;DR: In this article, the bond durability of GFRP bars in concrete when subjected to harsh environments was investigated and the durability performance in terms of the failure mode, weight loss, relative dynamic modulus of elasticity, durability factor, as well as the bond strength was measured and investigated accordingly.
Abstract: This study presents an experimental investigation on the bond durability of GFRP bars in concrete when subjected to harsh environments. The pullout specimens having different concrete covers were designed based on a created database to demonstrate the generality of the current experimental program. The freeze-thaw (FT) cycles, alkaline-saline (AS) solution, and both coupled effects were used to simulate environmental conditions in cold regions. The durability performance in terms of the failure mode, weight loss, relative dynamic modulus of elasticity, durability factor, as well as the bond strength, were measured and investigated accordingly. The test results revealed that the concrete cover with three times of the bar diameter was not sufficient to resist the environmental agents when exposed to weathering, including FT cycles, in which all the pullout specimens failed by concrete splitting. The coupled scenario of FT cycles and AS solution was observed to be the worst case among all the environmental conditions. Moreover, the analytical models: modified Bertero-Eligehausen-Popov (mBPE) model and Cosenza-Manfredi-Realfonzo (CMR) model, were calibrated by considering the environmental influences based on the experimental data to better demonstrate the degradation of GFRP-concrete bond.
TL;DR: In this paper, a series of TBC samples with carefully prepared Al2O3-based TGO of different thicknesses were used for both the burner cycling and the furnace cycling tests.
Abstract: Two types of typical thermal cycling tests are used for the evaluation of thermal cycling lifetime of thermal barrier coatings. Those are the burner cycling test with a thermal gradient and the isothermal furnace cycling test. There are diverse explanations to test results up to now. Although certain correlations should exist between the results obtained by two types of the tests, no evident parameters in two tests were directly related, possibly due to large range of difference test conditions. In this investigation, a series of TBC samples with carefully prepared Al2O3-based TGO of different thicknesses were used for both the burner cycling and the furnace cycling tests. The relationships between thermal cycling lifetime and TGO thickness were obtained for two types of the tests. It was found that TGO thickness presents the same influence tendency despite of different types of thermal cycling test. The results reveal the existence of the critical TGO thickness by which the transition of failure mode takes place. Moreover, the values of the critical TGO thickness for two tests are comparable. The results evidently suggest that the lifetimes during different thermal cycling tests can be correlated by TGO effects on failure behavior. However, it is clear that the apparent dominant driving factors to TBC failure are different in two types of tests. Accordingly, the burner cycling test could be used for optimizing the durability of ceramic top coat by separating the effect of individual factors through test condition design, while the furnace cycling test results represent the integrated TBC durable performance of the bond coat and top ceramic coating.
TL;DR: In this article, a parametric study was carried out to investigate the effect of surface preparation method, primer, number of CFRP layers and exposure duration on the failure modes and tensile capacity of double-strap joints.
TL;DR: In this article, the effects of weathering on durability and deformability properties for three different types of granitoid rocks were investigated, and the results indicated that uniaxial compressive strength and elastic modulus dramatically decrease with increasing weathering grade.
Abstract: In this paper, the effects of weathering on durability and deformability properties for three different types of granitoid rocks were investigated. Five weathering grades ranging from fresh to completely weathered rocks were considered for each rock type. Deformability has been evaluated based on failure strain, tangent and secant modulus. For measuring these parameters, at least five uniaxial compressive strength tests with axial strain recorded were conducted on each weathering grade. To assess the weathering effect on the durability behavior of these rocks, a slake durability test was performed up to 40 cycles. The obtained results indicated that uniaxial compressive strength and elastic modulus dramatically decrease with increasing weathering grade. After moderately weathering grade, remarkable damage was observed in the structure and fabric of considered rocks. The results from slake durability tests showed that the slake durability index for each weathering grade has a certain changes trend which can be used in determination of the weathering grade and the long-term durability assessment. Moreover, the results showed that for evaluation of the long-term durability of the mentioned rock types, at least eight cycles should be considered, while two cycles were sufficient for estimation of weathering grade.
TL;DR: In this paper, the authors investigated the induction healing behaviors of both warm mix asphalt and hot mix asphalt through damage-healing-damage test and compared them through damagehealing damage test.
TL;DR: In this paper, the validity of different practically applicable single pellet durability/compressive strength methods as predictors for ISO 17831-1: 2015 standard fuel pellet performance was determined.
TL;DR: In this paper, the effects of pumice and metakaolin (MK) on the durability and microstructural properties of self-compacting concrete (SCC) are investigated.
Abstract: In this study, the effects of pumice and metakaolin (MK) on the durability and microstructural properties of self-compacting concrete (SCC) are investigated. A total of 10 mixtures includin...
TL;DR: In this paper, the durability of recycled aggregate concrete (RAC) in building construction has been investigated, especially in terms of chloride penetration, and it is shown that this material requires particular attention.
Abstract: With the utilisation of recycled aggregate concrete (RAC) in building construction, the durability of this material requires particular attention, especially in terms of chloride penetration. This ...
TL;DR: In this article, the Cement Functional Performance (CFP) metric was introduced to evaluate the effect of the CFP on the environmental performance of three cements, including Portland cement, Portland cement and Portland cement.
TL;DR: In this article, the effects of Metkaolin (MK) and Alkali resistant glass fibers on the performance of self-compact concrete have been evaluated and it was found that glass fibers did not impart positive effect on the compressive strength of concrete.
TL;DR: In this paper, an ettringite-based material was synthesized by hydration of calcium sulfoaluminate cement for heat storage as durability is a key criterion for selecting a heat storage material.
TL;DR: In this paper, the durability of two types of fiber-reinforced polymer (GFRP) rock bolts were investigated and compared to two different types of VE/glass fiber reinforced polymer (FBRP) bands.
Abstract: This study was conducted to investigate the durability of two types of vinyl-ester/glass fiber-reinforced polymer (GFRP) rock bolts [solid and hollow (tubular) GFRP bars] that were subseque...
TL;DR: In this paper, the effect of stabilisation by alkaline activation and silicon based admixture on the mechanical properties, moisture buffering capacity and durability of an earthen material for building construction was investigated.