Applied Mechanics and Materials Vols. 204-208

Abstract: Based on the recycled asphalt pavement material rooted out during road net reconstruction, this paper uses modified rejuvenating agent technology to study the reclamation performance of recycled asphalt pavement material, the mixture is AC-16 designed with new and old asphalt mixture. The results show that modified rejuvenating agent technology can improve the high temperature stability performance, the low temperature crack resistance performance and the moisture susceptibility performance of recycled asphalt pavement material effectively.

Abstract: The chloride binding mechanisms of different mineral admixtures under the condition of stray current and NaCl solute were researched. The electric potential titration was used to measure the content of total chloride ions and free chloride ions. The results show that using of mineral admixture could effectively inhibit the destructive action of the stray current to the stability of bound chloride ion in cement paste. Among all, the most effective mix proportion on chloride-induced corrosion is the mixture with only slag, then the double mixing of fly ash and slag, the last comes the mixture with only fly ash.

Abstract: In this article, simulation tests of chloride binding were made under the condition of sodium chloride as an internal admixture while loaded with stray current externally. Through the potential titration method, free chloride ion concentration Cf 、 total chloride ion concentration Ct and chloride binding rate RCl were determined. The results show that: With the increase of the strength and action time of the stray current, the number of internal free chloride ions in the cement paste increases while that of the corresponding bound chloride ions reduces significantly, leading to the decrease of chloride binding rate. The relationship between chloride binding rate and the two can be shown as follows respectively:RCl=50.754e(-I/28.258)+42.532、RCl=63.427 e(-T/8.238)+27.325.

Abstract: In order to study the performance of the joint between gangue concrete filled steel tubular column with through rebar and gangue concrete beam under the monotonic loading, element analysis model, which is taken into consideration the material nonlinearity, the geometrical nonlinearity and the contact nonlinearity, is established by finite element analysis software ABAQUS. The results show the force transferring mechanism, the stress distribution, the failure model and the load-displacement curve of the joint under the monotonic loading. It indicates in this paper that the joint between gangue concrete filled steel tubular column with through rebar and gangue concrete beam has such numerous advantages as high bearing capacity, large stiffness and good performance. Meanwhile, the paper provides the calculation evidences to analyze the composite construction of gangue concrete filled steel tubular column and the results can be used to make the analysis on the practical structures.

Abstract: This paper presents the study on mortar specimens exposed to three kinds of Na2SO4 solution(0.5%,5%and10%)and different drying-wetting cycles(20,30,40and75). Influence of cycle number and solution concentration on mechanical behavior, mass and appearance of mortar specimen was analysis. The results show that surface of specimen in 5% and 10% solution shows obvious desizing, sandiness and some crack at 75 drying-wetting cycles. In different solution concentration, mass of specimen shows a trend to increase firstly then decrease lately. The increasing and declining separately of specimen mass are more obvious in high concentration solution. In three kinds concentration of solution, peak stress and modulus of elasticity of specimen show the same trend to increase in early erosion stage and decrease in late erosion stage. Change rate of mechanical behavior of specimen in high concentration solution is larger than that of in low concentration solution at early and later stage separately. On the contrary, peak strain show a trend to decline firstly then increase lately.

Abstract: In this paper, studied on the local compression on the center of plain concrete square column, by using finite element analysis found its stress distribution is approximate to strut and tie models and established strut and tie models of concrete subjected to local compression.

Abstract: Mix design of the steel fiber reinforced concrete was analyzed based on the engineering conditions. It was indicated by comparing with the strength values of steel fiber reinforced concrete (CF40) and ordinary concrete (C40) that the tensile strength of the steel fiber reinforced concrete increased about 70%, the compressive strength increased about 10%, the initial cracking strength increased about 150%.The reasonable construction technologies were used in mixing, transportation, pouring, vibrating and curing of the steel fiber reinforced concrete in order to ensure quality of the construction.

Abstract: After the pilot study about different-aged ceramsite concrete specimens, the curve and the formula about the ceramsite concrete splitting strength with age developing are obtained, the curve and the formula about the relative bond strength with age are analyzed, it provides a theoretical basis for the project production of ceramsite concrete practice.

Abstract: Warm recycled asphalt mixture can reuse the waste asphalt mixture via warm technology. In this paper, the waste mixture was reclaimed and analyzed. Warm recyclings with different propotion of reclaimed mixtures were designed. With the standard rutting test and Hamburg rutting test, the hot temperature stability of the warm recycling was evaluated. Conclusions on rutting resistance stability of warm recycling are drawn.

Abstract: Through test on compressive strength of concrete and mass changes, the effects of solution concentration and temperature on speed of concrete sulfate attack were investigated. The results show that, the speed of attack is accelerated with increasing concentration and temperature, as well as the decreasing of the size of the specimen, sulfate attack speed at 45 °C sodium sulfate solution soak with wet and dry cycle is insignificant difference with at 20 °C.It is suitable to adopt compressive strength as the assessing criterion of the sodium sulfate attack.