Advanced Materials Research Vols. 535-537

Abstract: In this paper, of the slag composition, stability and slag particles indicators of concrete performance, demonstrated use of steel slag to do the Complete Works of material, steel slag powder admixture with high wear resistance, water resistance slag cement preparationthe feasibility of high-performance cement concrete.

Abstract: One of the main benefits advertised with the use of warm mix asphalt (WMA) is the decreasing aging of the asphalt binder resulting from the lower production temperature compared to conventional hot mix asphalt (HMA). Some tests were performed to determine the asphalt binder aging properties from WMA and HMA. Asphalt binders were recovered by extraction and distillation from asphalt mixtures premixed at different temperatures (140°C, 160°C, 180°C for HMA, 100°C and 120°C for WMA) in the mixing plant. Penetration@25°C, softening point (R&B) and rotational Brookfield viscosity tests were carried out. Results show that the aging of asphalt binder increases as the mixing temperature is elevated, and remarkably accelerates at the temperatures higher than 150°C. Warm mix asphalt (for example, mixing temperature at 100°Cor 120°C) can greatly reduce the aging of asphalt. Aging of the asphalt binder is one of the factors that would affect the mixture’s fatigue life. Four-point beam fatigue test samples were mixed and compacted at 140°C for HMA and 120°C for WMA, and fatigue tests with a frequency of 10 Hz and three constant strain levels (150 micro-strain, 300 micro-strain, 450 micro-strain, respectively) were performed. Results show that WMA’s fatigue life was higher than the control HMA, which indicates that it may reduce aging of asphalt binder and improve fatigue performance of asphalt mixture at lower production temperatures.

Abstract: Fair-faced concrete is a neotype constructional material. It is exposed to the natural environment directly as decorative walls in the acting process, so the request of durability of the concrete is much higher. Through comparison testing, data collection and analysis, find out the difference of durability of fair-faced concrete in different proportioning. It has positive significance to the selection of raw material and construction technology.

Abstract: The damp and efflorescence for building bricks are the common disease of material. These phenomena may influence severely the building durability and indoor-air sanitation. From a macro perspective, the efflorescence of brick construction is related to the moisture condition of different masonry materials. Moreover, the growth mechanism of efflorescence has caused by the M.C. and the elapsed time being affected with damp and efflorescence from a micro perspective. Therefore, this article is focus on the mechanism of brick damp. This study uses systemic experimental design method and conducts a large number of fundamental experiment on damp and efflorescence of sand-lime bricks. From the microscopic measurement, the pathological mechanism of efflorescence for bricks and the variation on its M.C. are manifest. This research results may provide the suitable conservation strategies of repair engineering for reference.

Abstract: In recent decades, use of fibre reinforced polymers (FRP) materials has become very popular for strengthening / re-strengthening of reinforced concrete (RC) structures. This includes flexural and shear strengthening of RC structural members such as slabs, beams and columns.In this study, a computerized analytical model is presented to predict the load-deflection response of flexure critical RC beams externally strengthened with near surface mounted (NSM) CFRP laminates. The analyical model utilizes constitutive material properties of concrete, reinforcing steel, CFRP laminate materials, strain compatibility, sectional analysis to develop moment-curvature relationships, which then are used to generate the load-rotations and load-deflection of the flexure critical RC Beams strengthend with NSM CFRP laminates. For validation of the analytical model, the predictions of the analytical model are compared with the experimental results of flexure critical RC beams strengthened with NSM CFRP laminates and the comparisons are judged to be good.As a part of the experimental investigation of this study, a series of 18 full scale beams Reinforced Concrete Beams strengthened with carbon fiber reinforced polymer (CFRP) laminates will be tested in flexure and shear. The results of flexural tests will be analyzed and compared with the predictions of the analytical model.

Abstract: Study on water-rock interaction in transitional zone through the mixing of seawater and freshwater in different proportion and water-rock Interaction simulation experiments, In the mixing process of sea and freshwater, mixing is the basis of the mechanical mixing with complex chemical process, Total Alkalinity and pH values significantly increase, while the conductivity decreases significantly, calcite and gypsum saturation index increase significantly, while PCO2 reduces. In the course of water-rock role, the saturation indexes of gypsum elevate from -1.06 ~ -0.71 to -0.86 ~ -0.50 after interactions between mixed solution of various proportion and aqueous, which indicates that gypsum dissolves. The saturation indexes of calcite reduce from 0.69 ~ 1.07 to 0~0.10, which indicates that calcite precipitates in the process of experiment, calcite approaches to equilibrium in the end.

Abstract: Aging properties of tourmaline modified asphalt prepared by melt blending were studied. The change laws of aging properties of asphalt caused by different types and contents of tourmaline were studied systematically by rotated thin film oven tests (RTFOT), in which the indices of aged residues such as softening point, penetration and ductility were tested. The results showed that the anti-aging performance of asphalt was improved effectually with addition of tourmaline, the ratio of residual penetration and ductility increased, and the softening point increment of aged asphalt decreased. The improvement of anti-aging performance of asphalt reduced with the increasing mixing amount of tourmaline. Tourmaline anion powder (5000ions) was recommended to improve the anti-aging performance of asphalt.

Abstract: Eight non-plastic soils with different gradation are used for this research to study the appropriate choice of soil-cement mixture for a earth and rock-fill dam construction project. The properties of soil-cement materials are influenced by several factors, including type and proportion of soil, cementitious materials, water content, compaction, uniformity of mixing, curing conditions, and age of the compacted mixture. Based on the experimental results, the maximum dry density will increase with an increase in cement content for soils with low fines content. However, no significant variation was noticed for soils with higher fines content. For given cement content, the maximum density of soil-cement mixture also has a positive correlation with the average grain size, D50, and uniformity coefficient of gradation, Cu. Based on USBR criteria and experimental results, a minimum of 11% of cement content are suitable for soil-cement application on the dam construction. Coarser grain soils are more applicable than finer grain soils to soil-cement construction.

Abstract: Although small in size, indiscriminate littering of cigarette butts (CBs) can cause serious environmental impact. Several trillion cigarettes produced worldwide annually lead to thousands of kilograms of toxic waste. CBs accumulate in the environment due to the poor biodegradability of the cellulose acetate filters and, in doing so, they have become the most common litter item on our planet. This paper presents some of the results from a continuing study on recycling CBs into fired clay bricks. Physico-mechanical properties of fired clay bricks manufactured with different percentages of CBs (2.5%, 5% and 10%) and also of control brick samples are reported and discussed. To improve the properties, three different mixing times were tested with 7.5% of CBs incorporated in clay bricks, specifically at 15 minutes, 10 minutes and 5 minutes respectively. The impacts of these changes on physical and mechanical characteristics were evaluated. With 15 minutes mixing time, the measurement increased up to 114% and 12% for strength and density respectively compared to 5 minutes mixing time. On the other hand, values for water absorption, initial rate of absorption and tensile strength decreased by 22%, 29% and 5% respectively. Microstructure analyses of CB bricks were also investigated using ESEM. Attempts were also made to improve the properties by incorporating 3% of steel fibre into CB brick samples. Nevertheless, the addition of the steel fibre did not significantly improve the properties or the appearance of the manufactured samples.

Abstract: Tourmaline modified asphalt (TMA) was prepared by melt-blending process. The modified effect of tourmaline on base asphalt was studied systematically by penetration test, softening point test, ductility test and bending beam rheometer (BBR) test. Based on this, the chemical components of the samples were tested and the colloidal structures of the asphalt were analyzed. Experimental results showed that the temperature susceptibility of asphalt could be improved significantly with the addition of tourmaline. Softening point test revealed that the softening point of TMA was constantly increased with the increasing amount of tourmaline. BBR test indicated that the low temperature properties of asphalt were improved with the addition of tourmaline. The colloidal structure of the asphalt was not changed due to the addition of tourmaline, remaining Sol-Gel type, and a stronger stability happened with the increasing mixing amount of tourmaline.