Advanced Materials Research Vol. 1051

Abstract: In improving fiber reinforced cement-based composites, it is critically important to enhance the bonding strength between fibers and cement hydrate. Polypropylene (PP) fiber is a property enhancing additive, commonly used in cement-based composites. In this study, we tried to modify the surface properties of PP to enhance its bonding with calcium silicate hydrate (C-S-H). The surface was at least partly converted from lyophilic to hydrophilic by partial oxidation using potassium dichromate. The change in surface properties was examined by FT-IR, AFM, SEM and contact angle. The appearance of peaks at 1635, 1650 and 3200 cm^-1 in FTIR spectra for the treated PP, indicated the adsorption of water molecules on the surface, verifying the increase in hydrophilicity of PP. The AFM observation depicted that the roughness of partially oxidized PP surface was significantly increased. The contact angle was reduced due to the increase in hydrophilicity of the PP surface. However, the tensile strength of PP fiber had no significant reduction after being subjected to partial oxidation. Finally, AFM and SEM observations have shown that treated PP film bonded to C-S-H more tightly than that of original PP. It is suggested that partial oxidation of PP is an effective method to improve cement-based composites.

Abstract: The greenery policy in the green building design concept is an important topic and it also plays the significant role of natural protection and CO2 reduction to the environment. In Taiwan, the good policy is not yet a popular one, because some special reasons are existed really. Behind this paradox are the traditional concepts of Fengshui to the buildings funders, so that the greenery design comments in the green buildings design index may include some of these traditional concepts. It recommends not just the calculation the reduction of CO2 for each kind of trees. Moreover, the different species selection of garden planting for variant location of building site should also be studied and make some recommends. It can be believed that will improve the acceptation level of green building design to the popular and make the green building design really more reasonable.

Abstract: With the rapid development of marine exploration, the scale of offshore structures is getting large. It makes the slipways of marine construction site under critical bearing capacity and results in high-risk. Accurate evaluation of load responses of slipways can ensure the safety during construction and launching process and make use of them efficiently. Focusing on the issue, APDL technique is used in this paper to assessing mechanical performance of slab of the heavy slipway with maximum building capacity currently. Unfavorable live load distribution and contact conditions of panels are demonstrated under various serving conditions.

Abstract: Life cycle inventory (LCI) involves creating an inventory of flows from and to nature for a product system, which is a prerequisite of life cycle assessment (LCA). This paper conducts a comparative analysis of available inventories of cement produced in China and points out the reliability of these inventory results. 1 ton cement was chosen to be the functional unit, and the system boundary was defined from cradle to gate. In the process of cement production, many pollutants will be emitted, so only the four main emissions (CO2, NOX, SO2 and dust) are considered. The analysis showed that the reliability of cement inventories is affected by inaccurate or non-representative data, and all results are difficult to compare due to the varying system boundaries.

Abstract: In this paper, θ-EFG(theθfamily of methods –Element Free Galerkin) method is developed and adopted for the simulation of chloride diffusion in concrete. Diffusion of chloride ions is generally assumed to follow the Fick’s second law and its solving process usually adopts finite element and finite difference method. θ-EFG is a meshless method which uses a moving least square approximation in space domain, then uses the θ family of methods in time domain. Some discussions and One dimensional examples are carried out. The computational results compared with the analytical solution are shown that the relative error norm that time=20years, chloride content of different depth and depth =45 mm, chloride content are about 0.5% and 1% respectively.

Abstract: This paper designed the self-insulation concrete block meeting the energy-saving standard in northeast severe cold zones and introduced the whole design process of this new self-insulation concrete block. The size of the block is 390mm*280mm*190mm. We designed 15 types of block altogether, used ANSYS finite element software to analyze the combined influence of thermal engineering, mechanics and unit weight, got the best block type Q3 and optimized it twice in mechanical property and thermal performance, made the load-carrying capacity of the self-insulation concrete block tend to be more reasonable, and improved the thermal performance at the same time.

Abstract: Aim of this work is to investigate the feasibility to implement structural mortar containing forest biomass ash (FBA), produced by a local power plant, in partial replacement of cement. Chemical composition, morphology and pozzolanicity of ash have been evaluated using Energy Dispersive X-ray analysis (EDX), SEM and Chapelle test respectively. Furthermore, fresh state properties and drying shrinkage, compressive and flexural strength of the mortars at different curing times have been investigated. Forest biomass ash at replacement levels of 0%, 10%, 20% e 30% by total binder weight has been used. FBA has been found to show only a very moderate pozzolanicity, while it adversely affect workability of the fresh mortar and compressive strength and drying shrinkage of the hardened mortar. Nevertheless, at a replacement level of 30%wt and after 28 days of curing, mortar showed a compressive strength above 30MPa.

Abstract: The character of the Fly ash of Circulating Fluidized Bed Boiler (CFB Fly ash) is greatly different from that of Pulverized coal furnace for its high unburned carbon. In order to make effective use of CFB Fly ash in concrete, carbon content was decreased by simulated fluidized bed combustion in laboratory and a series of concerned experiments were carried out on CFB Fly ash. The experimental results indicate that CFB modification Fly ash is possible to be used in concrete to partially replaced cement. It is a valuable reference for CFB Fly ash technical engineers.

Abstract: The use of glass-fiber-reinforced polymer (GFRP) bar to replace steel reinforcement in concrete structures is a relatively a new technique. The GFRP bars possess mechanical properties different from steel bars, including high tensile strength combined with low elastic modulus and linear stress–strain relationship up to failure. Therefore, design procedures and process should account for these properties. This paper presents the experimental work on the flexural behavior of concrete beam reinforced with GFRP bars and strengthen with CFRP plate. A total of ten reinforced concrete beams reinforced with either steel and GFRP bars were cast and tested under four point loads. Eight concrete beams (200x250x2800mm) were reinforced with 13mm diameter GFRP bars together with strengthening using CFRP plate and two control beams reinforced with 12mm diameter steel bars were tested. The experimental results show that although the stiffness of the beams reduced but the ultimate load of the GFRP reinforced concrete beam is bigger than steel reinforced beam. It was also found that strengthening using CFRP plate will further enhanced the flexural performance of the beams with GFRP bars.

Abstract: The main aim of this paper is to evaluate the influence of the recycled expanded polystyrene as lightweight aggregate on the mechanical properties of lightweight cement mortar when subjected to high temperatures.Various tests have been carried out on different mixtures of mortar. The water/cement mix proportion has always been the same and only the nature of the aggregates has changed, with a partial replacement of the conventional aggregate by recycled ground EPS (EPS-G) with values ranging from 10% to 30%, achieving significant results in relation to exposure to high temperatures. In this research, the samples have been subjected to different temperatures of exposure, in order to analyze the influence of the lightweight recycled arid dosage in the mechanical properties of mortars.The results of this study show the ability of mechanical response at high temperatures with light mortars EPS-G. This study shows how this new mix can be used in different building types, optimizing construction materials and reducing mortars density while transforming a residual product into an active product.