Applied Mechanics and Materials Vols. 584-586

Abstract: The influence of insulation firewall on structure stiffness and the mechanical property of firewall in plane have been more mature in the academic research, but its out-of-plane mechanics is not complete at home and abroad. In this paper, static loading test of aerated concrete block filler wall was designed. Through the cracking loads, ultimate loads, failure loads and load-displacement curve of six walls, we make judgment of the impact on infill wall out-of-plane properties and failure morphology. The results indicate that the mainly failure pattern is horizontal crack and diagonal crack, the destroy position is concerned with the strength of four boundary constraints and the load capacity of infill walls can improve greatly after cracking, the height-thickness ratio is the decisive factor.

Abstract: The basic mechanical properties of the insulation board in external thermal insulation system are studied in this paper. According to the structure of the board, the relevant tests are designed, which includ the plate bearing capacity, the bond strength, the compressive strength and the flexural strength. The test results show that the security performance of the composite insulation board is high and bonding strength is good, compressive strength is high in the case of meeting the basic technical requirements. Besides, with the increase of the insulation board’s thickness, its flexural strength would increase.What’s more, due to the mesh effect on internal reinforcement, failure process has a certain ductility.

Abstract: Buton Rock Asphalt is a natural hard asphalt which is relatively rich in asphaltene and very low in wax. Through researches and practices, it is proved that the mixture of a certain amount of rock asphalt into the petroleum asphalt for regular roads can considerably improve the adhesivity of asphalt and aggregate and the high-temperature stability, low temperature crack resistance and water susceptibility. Relying on Guangdong Shantou To Jieyang Expressway, this paper applies Buton Rock Asphalt (hereinafter referred to as BRA) to making 70 Aiptek (hereinafter referred to as the IRPC-70) be modified, tests and analyzes the asphaltene content of the BRA and mineral levels and studies the influence of the BRA content on performance of modified asphalt. In the mixture design phase, it studies the impact of aggregate gradation after the BRA accession, obtaining the correction factor of the key sieve’s pass rate. Finally, the BRA mix design and pavement performance has been studied by the test section.

Abstract: Applling Leeb hardness tester D punch, examined the steel hardness by two different ways of clamping method and coupling method respectively, studied the correlation of Leeb hardness and steel strength, compared the research results with related literature and Jiangsu province construction standard of DGJ32/ TJ116-2011. Through the research, the conclusion is larger that this research results and related literature, the reliability is very low which be used to infer steel tensile strength with the D punch testing Leeb hardness .

Abstract: As a new green building material, straw concrete are introduced about its mechanical properties and characteristics. Mechanical properties test such as prism compressive strength, elastic modulus and Poisson's ratios use standard prismatic blocks. Under different rate of corn straw, cement, sand and fly ash, test gets the full stress-strain curve. Results show that with increase of volume of corn straw, the prism compressive strength reduces significantly. Comparing with natural concrete, elastic modulus of straw concrete can reduces greatly. Poisson’s ratio reduces with increase of volume of corn straw. Fly ash could improve property of the material and replace cement, but excessive replacement will reduce the strength of material.

Abstract: A new Steel deck-concrete composite floor slabs was proposed that with the effect of het preservation and insulation, and the flexure performance of the slabs has been studied. Calculation method of flexural bearing capacity was put forward. Based on comparative and analysis experimental results, it has been verified that the applicability of new formula of flexural bearing capacity of the new slabs.

Abstract: A noval concrete structure strengthening technique which employs aluminum alloy plate of stiffened sections was presented. Aluminum plate width, stiffener number and height were considered for bond performance investigations. Based on the simlple shear test, three types of failure mode were observed in this study. Test results indicates that the couple effect of aluminum width and stiffener number is more remarkable than stiffener height for strengthening behaviour. A set of comparison over the behaviour of aluminum laminate were carried out among EBR, NSM and stiffened plates. It shows that the siffened plates can be used sucessfully in concrete strengthening.

Abstract: Cement mortar is one of the commonly used building material . The effect of erosion is widely seen after a certain time. Based on the method of simulated experiment, Erosive ions at different concentrations, different age under uniaxial compressive strength of cement mortar and the influence of stress strain relationship are discussed. The results show that ion erosion was evident on cement mortar. Especially, certain solution concentration of SO₄^2- can enhance the strength of cement mortar. This research has important reference value for the application of cement mortar in complex environment.

Abstract: The influences of Portland cement substituted by slag powder in a high proportion (50% and 70%) on the chloride penetration resistance of concrete were studied. The results show that: the penetrability of Portland cement concrete reduced by one grade if 0.5% water reducer is added, but the water binder ratio is not the decisive factor for the permeability. There is a negative correlation between 6h electric flux and compressive strength only when concrete with same cementing materials. High volume slag powder concrete has excellent resistance to chloride ion permeability, which declines further with the increment of slag powder quantity added, the permeability coefficient of the concrete with 50% and 70% content of slag powder is as low as 27.8%~32.3% that of Portland cement concrete.

Abstract: The effect of process parameters on dynamic recrystallization of GCr15 bearing steel was investigated by a single-pass compression tests using Gleeble-3500 thermal simulator. The results indicate that the flow stress decreases with the increasing of temperature and the decreasing of strain rate. The dynamic recrystallization rate increases with the increasing of deformation temperature. By regression analysis, the mean activation energy and the stress exponent are determined to be 435.1KJ/mol^-1 and 5.0505 respectively. Meanwhile, the kinetic mathematical model of dynamic recrystallization and constitutive equation are established.The relationship of peak stress, peak strain and Z parameters is founded by using the data of flow stress curves.