Advanced Materials Research Vols. 919-921

Abstract: The performance of the interface between FRP and masonry is one of the key factors affecting the behavior of the strengthened structure. A challenge is to better understand the potential failure modes, which are generally directly related to the interfacial behavior between the FRP composite and the masonry in masonry walls. In this research, the experimental program was focused on the bond behavior of GFRP strips externally bonded (EB) to brick masonry.

Abstract: The paper presents some considerations on the reliability of the available formulas to determine the shear strength of masonry reinforced with FRP (fibre reinforced polymer) material. In detail the outcomes of a model related to the Eurocode 6 is prepared in presence of not usual shear reinforcement as FRP mesh bars jointed to ten surface masonry through steel joints. The model considers the basic contribution due to the masonry material and then add the contribution related to the presence of a material as carbon bars that is characterized by higher behaviour in term of stiffness.

Abstract: The application of technique for order preference by similarity to ideal solution(TOPSIS) and analytic hierarchy process(AHP) in reinforcement scheme optimization for bridge is investigated in order to select the optimal scheme from several primarily feasible ones. This paper calculates every index through AHP and applies the improved TOPSIS method to normalize and sort the evaluation index values. Integrating TOPSIS and AHP may Consider both the subjective intentions of policy makers, but also to a certain extent, to avoid arbitrariness.A real project demonstrates that this method is effective and feasible.

Abstract: FRP is a newly advanced composite material, whose convenient construction technique and excellent rehabilitation effect are generally agreeable by the circles of civil engineering. The studies on FRP strengthened building are one of leading issues on the field of civil engineering. Based on large quantities of latest relative documents, FRP strengthened masonry walls are summarized, and some issues needed to be studied are also presented.

Abstract: For the lack of concrete strength, the outer wall of a cement fresh material silo cracking. Then the cracking structure members have been strengthened with externally bonded steel plates. The finite analysis software ABAQUS has been used to simulate the reinforced silo and the structural analysis software MORGAIN has been used to calculate the reinforcements in this paper. The simulation results show that, the bearing capacity of the silo has been improved with this strengthening method effectively. On the other hand it could be referenced to solve the problems of similar projects.

Abstract: The concrete building protection materials is widely used in the hydraulic and bridge engineering. It was found that integral silane treatment can improve the durability of concrete.Compared with other protective methods, Silicone protect materials is the most convenient and environmentally-friendly.The silicone materials can effectively block the invasion of harmful substances such as water and chloride ions, and prevent the occurrence of the freeze-thaw damage. Few studies reported the protective effects of silane material which have different molecular structures .We found that Silane with relatively long molecular chain structure have a slower evaporation rate .When the concrete surface treated with such a silane material,the concrete surface has a 22% longer time to dry, so that the depth of penetration increased 16% for a longer concrete infiltration reaction time. we also studied the impact of temperature and humidity on the drying time of silane material , found using a suitable surface moisture conditions can get better protection.

Abstract: This paper examines the load capacity and safety of reinforced concrete beam bridge strengthened with pasting steel plates and carbon fiber polymer technology, taking the Longwanggou Bridge built in Jungar Qi in 1980s,a coal-rich area in Inner Mongolia, for example, in accordance with the Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts (JTG D62-2004), and the Code for Design of Highway Bridge Strengthening (JTG /T J22-2008). The girders in superstructure of this bridge were strengthened by using pasting steel plate technology, while the capping beams of piers and abutments using combined technology of sticking steel plates and carbon fiber reinforcement polymer (CFRP). At the same time, the deck pavement and the expansion joints were replaced, with adjusting the continuous form of the bridge, to improve the integrity and its driving comfort. The results from the theoretical analysis and dynamic and static load tests on the bridge after strengthening have shown that it is safe and good in the integrity and reliable in the load capacity.

Abstract: Spalling phenomenon in concrete exposed to high temperatures, e.g. during a fire, can seriously jeopardize the integrity of a whole structure. Spalling risk analysis and evaluation has become the hot topic of research on fire-resistance behavior of concrete structures at present. Based on fuzzy pattern recognition, a model for evaluating spalling risk of concrete structures at high temperature is established according to the factors influencing explosive spalling. The influential factor set is composed of strength, water/cement ratio, fibres content, curing humidity, load level, and heating rate, whose weights are determined by their relative importance. Good agreements between the results of spalling risk prediction and the fire test show the capability of the proposed model in assessing the spalling risk of concrete structures at high temperature, which will provide important reference for the fire resistance design of concrete structures.

Abstract: A new failure assessment curve of pipeline containing crack is provided in this paper. The new failure assessment curve is based on the J integral calculation method of the effective remote stress, and it is as simple as the R6 option 2. The result of the new failure assessment curve is as accurate as the result of the curve based on strict J integral. Moreover, the new failure assessment curve could be used for any stress-strain relationship material, including Ramborg-Osgood (R-O) material and non-R-O materials under monotonic increasing loading, such as long plastic yield plateau steel. The new failure assessment curve is applied to a case that came from the three pipes burst in a proof test of an oil pipeline. Comparison with the result in the proof test shows the result of the new failure curve presented in this paper is accurate.

Abstract: This paper mainly determined free chloride ion concentration of concrete beams of two kinds of water cement ratio (0.45and0.60) and bending load (0.00F_max, 0.30F_max, 0.45F_max and 0.60F_max) after 240 d in marine environment and compared the effect of different load conditions in the same water cement ratio on the free chloride ion concentration. The results show that the concentration of free chloride ion in tension zone of concrete increases with the increase of load level, the concentration of free chloride ion in compressed zone of concrete decreases with the increase of load level; under the same bending load level, the concentration of free chloride ion in concrete increases with water cement ratio.