Advanced Materials Research Vols. 535-537

Abstract: This paper reports the drying shrinkage and compressive strength results of cement pastes with fly ash and silica fume. In this study, Portland cement (PC) was used as the basic cementitious material. Fly ash (FA) and silica fume (SF) were used as cement replacement materials at levels of 0%, 5%, 10%, and 15% , 40%, 35%, 25%, and 15% by weight of the total cementitious material, respectively. The water/cement (PC + FA + SF) ratios (w/c) was 0.28 by weight. The samples produced from fresh pastes were demoulded after a day; then they were cured at 20 ±1°C with 50 ± 3% relative humidity (RH) until the samples were used for drying shrinkage and compressive strength measurement at various ages. The results show that drying shrinkage and compressive strength increase with increasing SF content, and the optimum composition of blended cement pastes is the cement paste with 30% fly ash and 10% silica fume, which possesses lower drying shrinkage values than that of plain cement paste and higher early age strength than that of blended cement pastes with fly ash. Furthermore, a linear relationship is established between compressive strength and drying shrinkage. By comparing the development of compressive strength and the drying shrinkage deformations, it appears possible to predict the drying shrinkage according to the acquired compressive strength.

Abstract: This paper has analyzed the existent patterns of the deep carbonized woods to building skins from the level of the relative independence and the integration for skins and structures. Combining with the physical and chemical properties of the deep carbonized woods, the paper discusses how it expresses the aesthetic significance as the building skins. Meanwhile this paper summarizes as a kind of new woods, the ecological significance of the deep carbonized woods to future development, which including four aspects for avoiding the urban heat-island effect, extending environment life cycle, contributing to the process and assemble of standardized components as well as earthquake resistance and disaster mitigation.

Abstract: The complicated counterbalance system of steel ring and concrete-ring，rigid-frame and concrete-plate was analyzed and simplified under the restrain deformation and strains. The material parameters of early-age concrete are measured. Based on these work, the corresponding mechanical models were established and a special tool was employed for the meshing of model, and then, internal stress and strain induced by shrinkage of early-age concrete on restrained conditions were studied by FEM. The self-induced tensile stresses and strains in the restrain concrete can be calibrated，on the basis of which the elastic strains and tensile stresses would be calculated. So, the results of the numerical simulation reveal the law of the stress and strain distribution perfectly. It is significant to contrast the restraint characters of steel-ring and rigid-frame. The early-age shrinkage behaviors can be studied in depth.

Abstract: The experiment focused on the contrast with rock breaking effect of impacting water jet by modulation of chaos and common cavitation jet. Investigated the influences of various water jet parameters and conditions on rock breaking, such as standoff distance, pump pressure, transverse speed and erosion time and the mass loss and erosion depth were measured in the experiment. The results show that the impacting water jet by modulation of chaos can efficiently use the energy of water jet and increase ability in rock-breaking, which will have a wide application prospect in high pressure water jet technology field.

Abstract: Rutting in asphalt pavements continues to create problems for pavement. The aim of this study was to analyze the influence of different gradation composition, asphalt dosage, temperature and dosage of anti-rutting agent on high-temperature stability of cosely gap-graded bituminous mixture. To achieve this objective, 171 different rutting specimens using different mix parameters were analyzed for their the high-temperature stability. The mix parameters include: three types of aggregate gradation, five types of asphalt dosage, four types of temperature and five types of anti-rutting agent dosage. Study results indicate that adding proper content of coarse aggregate can play occluding and wedging role in aggregate mixture. The optimal bituminous dosage in rutting test are lower 0.1%~0.3% than that in Marshell test. At 65°C, the high-temperature stability of the cosely gap-graded bituminous mixture is not able to meet the requirement of standards. The optimal dosage of anti-rutting agent are equal to 0.3% in case of no increasing bituminous dosage.

Abstract: The civil structure traditional dwelling have strong regional characters in Tianshui & Guanzhong .Through analysis of the characteristics of the adobe wall material, and to sum up the features of the construction techniques and structures , and puts forward the objective cause of the building materials of the large area used .

Abstract: Two experiments of direct sampling and sampling after 4.75mm sieve were prepared for the research on RAP (Reclaimed Asphalt Pavement)gradation and its variability. The results indicate that RAP gradation fluctuation causes the difficulty of controling recycled mixture gradation and the adverse impact on stability of recycled mixture. The method of sampling after 4.75mm sieve can effectively control RAP gradation fluctuation before recycled and reduce adverse impact on recycled mixture in the text.

Abstract: Combined with the equilibrium condition, the formula of vertical average sediment concentration has been derived from the vertical two-dimensional suspended sediment diffusion equation. Based on analyzing and comparing two hydrodynamic formulas, a new formula of sediment carrying capacity has been deduced. Some river and inshore sediment data has been collected to validate the formula and find that the new formula has higher accuracy and applicability comparing with the two hydrodynamic formulas, it shows that the new formula has a high application value.

Abstract: A flow and sediment mathematical model was built under three-dimensional hybrid coordinate to simulate Wenzhou Oufei tidal flat and its neighboring sea area, and the verification was down. The calculation results and the observed data are identical well. In estuary area, the sediment concentration is the highest, then outside the estuary. In Oufei tidal flat area, the sediment concentration is relatively high, and it decreases gradually towards the open sea. Through the simulation, the characteristics and the basic law of sediment concentration distribution was reproduced.

Abstract: The new building wall material ALC ( Autoclaved Lightweight Concrete) wallboard is solid composite sandwich panel. The existing standard requires that the ALC wallboard must meet resistance performance when it is laid into the wall. The evaluation index is determined and exists error. In order to guarantee the ALC board has better suitability，and make up the deficiency of the current specification. Through the impact resistance performance test of the ALC wallboard， study the dynamics characteristics under impact loading. Do some further analysis of the ALC wallboard dynamic characteristics damage problems through the change of frequency and the damping ratio. In turn， these changes can be the basis of structural damage evaluation. Laying a foundation for the ALC wallboard can better applied in practical projects.