Advanced Materials Research Vols. 287-290

Abstract: Phosphate based binders are high early strength materials with a short setting time. Usually, they are used as rapid repair material for concrete structures. The feasibility of a basalt fiber reinforced inorganic binder for strengthening concrete was studied. We successfully compounded suitable phosphate binder (PB) for concrete strengthening. In the current paper, phosphate binder was to adjusted to has excellent workability, suitable setting time and fluidity. Compressive strength of phosphate binder mortar, bonding strength between PB and Portland cement mortar, and strengthening effect of PB sticked basalt fiber on concrete beam were measured. Results showed that PB has excellent adhesion with Portland cement mortar. The strengthening effect of basalt fiber reinforced PB composite on concrete beam is evident. It is feasible that concrete strengthening by basalt fiber reinforced inorganic adhesive.

Abstract: To propose a prediction formula of compressive strength of concretes containing fly ash (FA concrete), over 1600 strength data are collected from previous studies and discussed in this study. In particular, the study focuses on developing strengths of FA concrete. The study deals with test data of concrete with wide range of FA replacement, namely 0-50% by mass of cement. Compressive strength at age of 7 days has strongly relation to the cement-water ratio, so the strength can be predicted by using only water and cement contents. In addition, early age strengths within 7 days can be estimated by using the Goral curve based on strength ratio. Strength after the age of 7 days can be predicted by using replacement ratio of fly ash because the strength ratios are proportional to the replacement ratio. Based on the findings, a simplified formula for predicting compressive strength at various ages is proposed in the paper.

Abstract: Fiber reinforced concrete is a commonly used special concrete. As enhancing the tensile and compressive strength and improving the durability of concrete, fiber reinforced concrete was used widely around the world. The characteristics and categories of the fiber reinforced concrete were introduced and the application status of that at home and abroad was presented. Some problems during the research and application were proposed and the application prospect of the fiber reinforced concrete was forecast.

Abstract: Since no super high CFRD with dam height more than 233m been ever built in the world, more problems of 270m high CFRD are still to be explored and solved. The 270m extra high Maji CFRD is to be constructed. In order to get stress and deformation characteristic of this dam, 3D finite element analysis was carried out. To make comparison on stress and deformation of Shuibuya dam which has been built, the Duncan-Chang E-B model parameters of Shuibuya dam, which was obtained by large scale tri-axial experiment, was used here to prediction this 270m high dam behavior. According to the calculation results, some beneficial conclusions were obtained and the design scheme of the 270m dam will be optimized.

Abstract: The energy consumption of concrete is considered as the research object,and the life cycle theory is applied in the energy consumption analysis of concrete. the life cycle energy consumption inventory analysis of concrete is set up,the concrete’s whole life cycle is divided into four stage. Each stage’s energy consumption is carried out a detailed analysis. Based on the inventory analysis, an energy calculation model of concrete is established .

Abstract: In order to investigate the progressive failure process of brittle rock, the mechanical properties of red sandstone from southeast Shandong province were systemic studied. The stress-strain curves and failure modes of samples under different strain rates were recorded as original data. Based on these data, the axial stiffness, the volume strain, the crack volume strain, and so on were deduced for further analysis. The crack initial stress and the crack damage stress were identified by Moving Point Regression Technique and stiffness curves. The influence of strain rate on the micro-cracking process and the ultimate compression strength of red sandstone were then studied. The results show that: as the strain rate increases, the ultimate compression strength first decreases and then increases as the strain rate increases, and the ratio of crack initial stress/ultimate compression strength and crack damage stress/ultimate compression strength decreases.

Abstract: Heat conduction in anisotropic materials is quite different from that in isotropic materials. Heat flux vector is commonly not perpendicular to the isothermal surface in anisotropic materials. The advantage and disadvantage of anisotropic materials were analyzed in this paper. The thermal conductivities at one point are not equal in all directions for anisotropic materials. The technique of double skin facade has been successfully applied in many building designs. The application of combining building envelope of anisotropic materials and double skin facade was proposed to avoid its disadvantage. Basing on the combination of anisotropic materials and double skin facade in building envelope, the indoor cooling and heating load decrease in summer and winter respectively. Especially in summer, the effect of energy saving is obvious since the partial magnitude of conductive heat in the envelope made of anisotropic materials could be brought out from the cavity of double skin facade by natural or forced ventilation through it.

Abstract: In this paper, preloaded specimen is used and confined by CFRP to act as structural concrete member in service. And the test to examine the behavior of the test piece has been carried on. After this, the strength and its influence factor has been analyzed. Referring the former strength model, the particular factor axial ratio B of the specimen this test has been taken into account.Then refering the existing model, the improvement has been made. And the new strength model for forecast to CFRP confined preloaded concrete is put forward, also it can be used as reference for reinforcing design of engineering.

Abstract: The aim of this paper is to study the influence of lithium-slag and fly ash on the workability , setting time and compressive strength of alkali-activated slag concrete. The results indicate that lithium-slag and fly-ash can ameliorate the workability, setting time and improve the compressive strength of alkali-activated slag concrete，and when 40% or 60% slag was replaced by lithium-slag or fly-ash, above 10 percent increase in 28-day compressive strength of concrete were obtained.

Abstract: Super-absorbent polymer (SAP) was used as a self-curing admixture for cement-based materials. Two types of super-absorbent polymer and effect of super-absorbent polymer on fluidity and mechanical properties of mortars were investigated. The performance of the mortars cured for different ages was tested. The results showed that SAP could play a role of reserving water and reserving water of SAP particles A with an average diameter of 180 mm was more effective than that of SAP particles B with an average diameter of 80 mm, the optimal performance of reserving water was obtained at 0.07 wt.% of SAP particles A; Mechanical properties of hardened mortars with SAP particles A were better than those with SAP particles B, the favorably experiment ratio was 0.05 wt.% of SAP particles A.