Advanced Materials Research Vols. 1065-1069

Abstract: Due to the growing the standard of living, bicycle interest has increased which concerns a negative effect in transportation. Although, bicycle road construction is increasing continuously, distress problem is occurred by empirical design which is conventionally used. To determine the optimum joint spacing, thin porous concrete pavement was constructed and measured with vibrating wire strain gauges. Joint spacing is varied in 1.5m, 3.0m, 6.0m intervals, with slab thickness 7cm. Early age behavior of thin porous concrete pavement is measured. As expected, more restraint occurred at the longer slabs.

Abstract: In order to investigate the carbonation resistance of shotcrete and the mechanical properties after carbonation, the accelerated carbonation test was carried out. The results indicate that the carbonation resistance of shotcrete is superior to that of normal concrete. With the increasing of carbonation depth, compressive strength and splitting tensile strength of shotcrete grew rapidly. The admixing of steel fiber can further improve the carbonation resistance, reduce the carbonation rate, and increase the splitting tensile strength of shotcrete greatly. Besides, based on analyzing the effects of construction technology and steel fiber of concrete for the carbonation resistance, a carbonation depth model for shotcrete was established. Key words: shotcrete; carbonation; steel fiber; mechanical properties

Abstract: Combined with engineering examples, describes the reasons for the large volume of concrete cracks proposed comprehensive measures to control cracks from all aspects of mass concrete harmful cracks eliminate achieved remarkable results, for the future of similar mass concrete construction provides some guidance .

Abstract: The optical fiber has been extensively used as a sensor in some special fields. Because the optical fiber exists crackles itself and also produce the micro-crack as well as local damage, the fatigue behavior of the optical fiber become the main problem we care about. This paper presents the experimental study on the fatigue performance of bare fiber under static, dynamic and cyclic load. The corresponding fatigue life index (Stress corrosion index) n can be obtained, which are 17.14, 11.83 and 5.88, respectively. The experiment data reveal that fatigue life index is related to loading mode and is treated as the indicator of crack propagation resistance of materials. Because dynamic and cyclic loads can induce additional damage, the fatigue life declines dramatically under the same stress levels.

Abstract: The concrete used in transmission lines are basically for foundations. The foundation concrete of transmission lines in corrosive environments has shown serious deterioration, which usually caused by concrete deterioration, rebar corrosion, degradation of bond strength between rebar and concrete due to various corrosive effects. Field tests are carried out in Wuhu area to research the durability of foundation concrete of transmission lines. And test results show that the concrete strength in the air is a litter higher than underground and the carbonization depth at the windward side is the largest of each foundation and the leeward side is the smallest, while those underground are close to zero.

Abstract: Compared with the river sand, manufactured sand’s particle type and gradation is relatively poor and the surface is mat .The manufactured sand also has a big effect on the workability of concrete. In this paper,the Equivalent powder paste’s volume of manufactured sand concrete was determined according to Mehta and Aitcin’s ideas for the preparation of HPC,at the same time,the equivalent powder paste volume is assumed as the cement paste volume in the experiment. The influence of polypropylene fiber on Manufactured sand concrete’s workability and Compressive strength were researched in the case of fixed powder paste .

Abstract: The results of this paper are being summarized in a series of articles categorized into the principal properties of the mortars, for example compression strength, admixtures, air-content and water cement ratio, and the impact of those properties on bond strength were analyzed. The second purpose of this article deals with the relationship between brick’s properties with bond strength. The results shown that those effecting factors mainly through make an influence on the amount of hydration products and the bonded area to determine bond strength.

Abstract: Mortarless interlocking blocks have the advantage of convenient construction and low cost, but establishing the geometry interlocking mechanism between horizontal blocks has been overlooked. Optimizing the shape of mortarless interlocking block. The connection of vertical direction in the form of a frustum of a cone, and the connection of horizontal direction in the form of trapezoid shape. This design proposal builds geometry interlocking mechanism between the block and its all adjacent ones. Setting cone and rectangular holes on block body, accordingly, block laying could forming taper vertical channel and rectangular vertical channel. The concrete of interlocking mortarless block has particularity, which is not suitable for “Mix Proportion Design of Ordinary Concrete Regulation” (JGJ55-2010) of China. This paper presents a platter idea to establish the concrete mix proportion design method of mortarless interlocking block, moreover, an example calculation and confirmatory experiment is dispensable.

Abstract: This paper describes the nondestructive evaluation of microstructure using laser-excited Lamb waves to detect the phase transformation in NiTi shape memory alloy sheets. Lamb waves were applied in the NiTi sheet using a pulse laser beam. Piezoelectricity transducers were used to receive the Lamb waves, the group velocities of which were measured using a time-frequency analysis method at different temperatures. Results show that a marked variation in the group velocity occurs during the phase transformation in the NiTi alloy. The dependence of group velocity on temperature provides a effective means of inspecting microstructure transformation in NiTi alloys.

Abstract: In this paper, a large rotation matrix for geometric nonlinear analysis of frame structures is developed by introducing the Rodrigues formula proposed by Argyris to modify the original rotation scheme of Bathe and Bolourchi. In the deduction, the large rigid body rotation of the beam element is decomposed into the relative translational displacements and the axial rotation respectively. Using Rodrigues formula, the large rotation matrix of rigid body can be calculated and sequentially the nodal transformation matrix of the beam element can be derived. And with this transformation matrix, the equilibrium equations of the beam elements established in the current configuration can be transformed into the original configuration, and then assembled and solved finally. The validity verification of the method would be presented and discussed in the part 2 of this paper.