Applied Mechanics and Materials Vols. 357-360

Abstract: Load-bearing aerated concrete block A7.5 B07 is applied to the construction , multi-storey masonry residential and cast-in-place structure over ± 0.00 of the residential is made of ceramsite concrete. The results of energy-saving test comply with the requirements of the existing building energy-saving design, exploring a new residential energy-saving system.

Abstract: Silane impregnation effects on concrete carbonization resistance are systemic researched, through determining blank and silane impregnation specimens carbonation depth, forming 6 mixture ratio cement mortar, treating with silane impregnation and then curing to 30d, 60d, 90d and 180d age naturally. Through XRD microscopic and water absorption test, the improving carbonization resistance mechanisms are analyzed from two aspects including cementations material hydration product concrete pore humidity.

Abstract: Water, chloride ion, deicing salt and freeze-thaw cycle are the greatest enemy of the concrete, leading to concrete corrosion damage, the concrete building protection materials is utilized widely in the hydraulic and bridge engineering. Using the silane materials to an immersion treatment can effectively block the invasion of harmful substances,the results showed that the deep penetration of silicone material formed a hydrophobic layer and provided an effective protection against water corrosion and chloride ingress. Such an organic silicon material is no evaporation of solvent, friendly to the environment, so is considered the most suitable for concrete protection.

Abstract: The mechanical behavior of integrated concrete/lightweight aggregate concrete-foam glass Sandwich blocks was tested in this paper. Foam glass plate was inserted and poured together into the Sandwich block. The compressive strength and the tensile strength normal to the interface were tested and analyzed. The results indicate that, the compressive strength of Sandwich blocks is mainly depended on concrete/lightweight concrete parts. The damage of Sandwich blocks in tensile test is due to the tensile strength insufficiency of foam glass plates. The bonding between the foam glass plates and concrete/lightweight concrete performs well whether in the compressive or in tensile experiment. It provides a tentative guideline to manufacture jointly poured concrete-foam glass Sandwich blocks.

Abstract: Experiment on the mechanical behavior of ceramsite lightweight aggregate concrete (LWAC) after elevated temperatures was conducted in this paper. The ceramsite LWAC test blocks were first heated at five temperature levels, 200°C, 350°C, 500°C, 650°C and 800°C. The corresponding loading test was carried on after they were naturally cooled down. Changes of compressive strength, elastic modulus and load-deformation curve after different levels of high temperature were analyzed. The results indicate that, the reduction of ceramsite LWAC prism compressive strength is faster than that of cubic compressive strength. Compared with normal-density concrete (NC), whether for cubic or prism blocks, the residual compressive strength ratio of ceramsite LWAC is obviously larger than that of NC. The load-deformation curve of ceramsite LWAC with the elevated temperature is gradually flatter.

Abstract: The main defect in concrete and other brittle materials was the crack in the materials which would cause the structures brittle fracture. So it is very important to study the development of cracks in the concrete structure. This article researched the criterion of the shortest distance from the crack tip to the plastic zone edge for concrete and other brittle materials based on the least distance in plastic zone theories. The numerical example verified that the proposed criterion could solve the low stress brittle fracture phenomena in engineering better.

Abstract: The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

Abstract: Self-compacting concrete (SCC) is a flowing concrete mixture that is able to consolidate under its own weight. The highly workable nature of SCC makes it suitable for placing in complex structural elements and in sections with congested reinforcement. Utilization of industrial waste products in the construction industry draws serious attention of many researchers and investigators. In this study an experimental investigation has been carried out to study the significance of blast furnace slag as partial replacement for coarse aggregate in fly ash blended self-compacting concrete. The coarse aggregate was replaced by blast furnace slag at 10% to 100% and various tests were conducted to determine the optimum level of replacement of blast furnace slag in self-compacting concrete. The specimens were subjected to compressive strength, split tensile strength and flexural strength tests in addition to fresh concrete properties. Slump flow, J-ring test, L-box, U-box and V-funnel tests were carried out for evaluating fluidity, filling ability and segregation properties of the fresh concrete. Based on the overall observations it could be concluded that an increase in slag proportion increases the strength properties and among the various percentages of replacement 30% is found to be optimum for maximum strength properties.

Abstract: Effect of plastic stage curing on long-term properties of high performance concrete (HPC) was studied, thereafter, the mechanism is also analyzed. Results showed that compared to compressive strength, the permeability of surface concrete (especially for silica fume concrete) was more sensitive to plastic stage curing, and deteriorations due to insufficient plastic stage curing cant be eliminated by later longer time of wet curing. Furthermore, the deterioration of pore structure and formation of microcracks were main reasons for insufficient plastic stage curing that affected properties of concrete.

Abstract: Confined concrete is superior to the normal concrete in anti-projectile performance. The concrete filled confining tube of relatively small radius would be in cracked-comminuted stage during the penetrating process of projectiles at relatively low velocity. Based on the linear pressure-volumetric strain relationship and the Mohr-Coulomb yield criterion, a dynamic cylindrical cavity expansion model for the penetration into confined concrete targets with lateral elastic confinement is proposed. Numerical results show that the lateral confinement improves cavity stress significantly, and the radius ratio of target to cracked-comminuted interface has little influnce on cavity stress for relatively low cavity expansion velocity.