Applied Mechanics and Materials Vols. 405-408

Abstract: The inorganic polymer concrete is a new environmentally material. Using the temperature - stress test machine to research its early cracking sensitivity, and compare it with the normal concrete. The deformation development process of inorganic polymer concrete consists three stages:early contraction, expansion, contraction to cracking; cracking temperature can effectively evaluate the overall cracking performance of concrete; the cracking temperature of inorganic polymer concrete is 14.2 °C, the normal concrete is 14.4 °C; the inorganic polymer concretes cracking stress is 2.658MPa, the normal concrete is 0.582MPa. The results show the inorganic polymers cracking performance is better than the normal concrete.

Abstract: The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.

Abstract: The intention of the research presented in this article was to study the basic physico-mechanical parameters of mineral lightweight renders. Both alternative and primary raw materials were used to modify the filling agent; namely utilized quartz sand, diatomite and hydrophobised perlite. Determining and evaluating the basic parameters of plasters with the modified composition enabled to assess the effect of substituting the filling agent within the particular designed formulas. Emphasis was placed on the parameters in the fresh and hardened conditions of the plasters – workability, water volume, density, compressive and flexural strength. It was found that by appropriately adjusting the water dosage then better parameters could be obtained than in the reference formula – commonly commercially produced renders.

Abstract: Dynamic response and damage mechanism of two-core sandwich panels with foam and honeycomb cores and glass fiber/epoxy composite sheets under low-velocity transverse impact are investigated. The emphasis is focused on the contact force response and crash mechanism of the two-core sandwich panels. Effects of configurations, impact energy levels and types of the cores on the dynamic response are investigated. A modified drop-test experiment is carried out to obtain contact force history of the two-core sandwich structures under different impact energies. The experimental results show that the 10:10 configurations for both honeycomb and foam core sandwich structures under lower impact energy absorb more impact energy than the other two structures. However, under higher impact energy, the honeycomb core sandwich structures of 15:5 configuration absorbs a little more impact energy than the other two, while for the foam core sandwich structures the 5:15 configuration shows a little better impact resistance. Results also show that when impact energy is low foam core sandwich structures do better in absorbing impact energy than the honeycomb ones.

Abstract: This paper studies how polymer alters the flexural toughness of concrete. By selecting five different types of polymer mixing into concrete; results indicate that polymer has obvious effect to enhance toughness of concrete evaluated by toughness index T. Microstructure of polymer-modified concrete were studied through environment scanning electron microscope, digital micro-hardness tester and nanoindentor, results indicate that polymer form the ionic compounds and reduce the crystallization of Ca (OH) ₂, acting as a flexible filler and reinforcement in concrete. Polymer also alters the microstructure at the aggregatecement interfacial transition zone.

Abstract: The 100 x 200 mm cylinder specimens are standard size to measure the compressive strength and modulus of elasticity. However, it is not enough for experimental data of mechanical properties of HPC about size effect. The aim of this study is to investigate the size effect of high performance concrete (HPC) using blast furnace slag (BS) for mechanical properties such as, compressive strength and modulus of elasticity. Therefore, in this study, Type A (100 x 200 mm cylinder specimens) and Type B (150 x 300 cylinder specimens) were prepared. Blast furnace slag is used as a replacement for ordinary Portland cement (OPC). The compressive strength, modulus of elasticity of harden concrete were determined in the laboratory.

Abstract: The waste rubber powder application key technology in cement based materials is to solve the rubber and cement based materials interface bonding problem. NaOH, PVA and KH560 modified rubber powder is added to the rubber mortar. The test results show that, KH560 modified rubber mortar compressive strength increased by 7.4% compared to the unmodified rubber mortar; NaOH modified rubber mortar flexural strength increased by16.7% compared to the unmodified rubber mortar; Compressive and flexural strength ratio lower 37.9%. Scanning electron microscopy and infrared spectra are analyzed from the test results microscopic aspect.

Abstract: In this paper, polycarboxylate superplasticizer (PC) was separated by ultrafiltration to investigate function on dispersion of various portions of PC. It is found there is a grading effect on the dispersion and adsorption of polycarboxylate superplasticizer, through fluidity and adsorption experiments.

Abstract: In this paper, the adsorption behavior of polycarboxylate superplasticizer (PC) on cement was examined. Through adsorption of PC, adsorption area of the molecule was calculated, and it is found that PC molecule would maintain curled shape when it was adsorbed on the surface of cement particles.

Abstract: The nanosized TiO₂ and luminescent materials were coated on PVC flexible composite material to get self-cleaning luminous PVC flexible composite building materials, the materials durable-polluted, luminous, reused properties and the adhesion property of the nanosized TiO₂ and luminescent material particles were tested and studyed. The experimental results show that the nanosized TiO₂ and luminescent materials finishing self-cleaning luminous PVC flexible composite building materials gain significant and good durability performance of self-cleaning and luminous functions.