Applied Mechanics and Materials Vols. 357-360

Abstract: Waste tires are increasing year by year, which can destroy environment without dispose promptly. The mixtures of clay, cement with tire granules have been used abroad. Its advantages are obvious,such as light, seismic resistance, seepage proofing and high strength etc. Through triaxial test of waste tire granules, cement and soil mixtures, by changing the ratio of tire granules, test results indicate waste tire granules can improve the properties of soil mixtures. The critical content of the tire granules is about 20% at the cement content is constant, when the cohesion and the strength of the mixtures can reach a maximum.

Abstract: Based on thermodynamic principles,this paper uses ANSYS to simulate thermal stress of the concrete piers and analyzes the main factors, namely, structure size, concrete strength, boundary conditions and freeze-thaw cycle system which affect thermal stress. We then draw the conclusion that the existence of thermal stress will make the concrete structure undertake cracking risk. Thermal stress difference in massive concrete structures is large and the influence of thermal stress on concrete structures is only limited to a certain size range; thermal stress inside the concrete increases with the increment of concrete strength grade; thermal stress inside the concrete decreases with the increment of boundary constraint conditions; the rate of change of thermal stress increases with the acceleration of freeze-thaw cycles. Meanwhile, we propose that through increasing the thickness of the protective layer and boundary constraint conditions properly, cracking risk of concrete structures can be reduced.

Abstract: The basic theory of the rebound method is introduced, and analytic solution of inverse regression equation for evaluating concrete strength of building materials is presented herein based on the inverse regression model. Furthermore, two engineering examples are given, satisfactory results are obtained using the analysis method. The analysis method can be also used to gain the presumption of strength for others building materials and solutions of other inverse regression models.

Abstract: Magnesium lightweight wallboard is a new kind of building wall materials in recent years. This wallboard has a light weight, and has the advantages of energy conservation and environmental protection, increase the use area of the buildings, easy to install and improve construction efficiency, etc. This paper designs one 1:1 cast-in-situ concrete frame of span 4.5m and net height 3.3m, and embed magnesium light wallboard in it. Applying level force with simulates wind load to the wallboard. In the experiment adopted two wallboards with different thickness and different connection ways with wallboard and frame. During the test observe the development of cracks, measured the horizontal displacement, the cracking load and ultimate load of wallboard. Test results show that the strength and displacement of wallboard can satisfy the requirements of the use of exterior walls, which can be used to building external wall with a certain height.

Abstract: Wheat straw alkali treatment has impacts on the strength of cement mortar and glazed hollow beads insulation mortar. The results show that the bending strength and bending strength of cement mortar specimen with 4% wheat straw are respectively 58.3% and 40.9% of the benchmark specimen, but bending-press ratio of the latter is 1.42 times of the former. The SEM images reflect the straws influences on the cement hydrate morphology, status and the influence of the number on cement mortar and glazed hollow beads insulation mortar. Compared with the latter, the former C-S-H gel is loose fibrous, failure to form a good network. In the thermal insulation mortar consistency and stratification of the same circumstances, with straw dosage increased, strength first increases, then declining. And folding pressure than in straw dosage is less than 24% more ideal. The SEM pictures show that network C-S-H gel decrease and loose fibrous C-S-H gel increased. At the same time, AFt gradually become attenuate and curly.

Abstract: The saline-alkaline geological environment is highly corrosive to the concrete. Aimed at the saline-alkaline geological environment, the article ascertains how to prepare frost resisting and anti-corrosive concrete with strong endurance.

Abstract: The asphalt emulsions were prepared using modified lignin amines as cationic emulsifiers. The effect of types and dosage of lignin cationic emulsifiers on the preparation and storage stability of asphalt emulsions were discussed by measurement of average particle diameter and Zeta potential of emulsions. The experiments show that the higher the surface activity of emulsifiers was, the smaller the average particle diameters of emulsions became. With the increasing of dosage of emulsifiers, the average particle diameters of emulsions descended. The storage stability of emulsions was improved distinctly when the lipophil dodecyl group was introduced into emulsifiers, which was attributed to good surface activity and enhanced mechanical strength of interfacial membrane for the alkyl chain of dodecyl group could be inserted in the asphalt particles.

Abstract: The paper reports how to use quartz tail-sands to produce aerated concrete block. Through studying hydro-thermal synthesis reaction, gas-forming and performance analysis, satisfied mix ratios and optimal technical parameters are set successfully. The results show that utilizing quartz tail-sands can make aerated concrete production which is in accord with Chinese national standards. It fully reflects the requirements of environmental benefits and building energy efficiency.

Abstract: this paper analyses the reutilization of waste concrete is feasible in technology, technical index, and its concrete recycling huge economic, environmental benefits.

Abstract: It is analysed on planting adaptability and structural adaptation of fired brick and tile waste in the road greening. Multi-level index system on impact of road green layer fill options is proposed.Fuzzy optimization model of multi-objective multi-level index system is built. It is evaluated that fired brick waste and soil, ecological concrete as filling material of planting layer to show the advantages of the application of the fired brick waste.