Advanced Materials Research Vols. 374-377

Abstract: Based on detailed consideration of the autonomic healing concept of microencapsulated healing agent, micro- bacteria induced calcite and shape memory alloys, our research team proposed a new self-healing technique coupled with of SMA and heat-melt adhesive. In this article, chemical stability and bonding strength with cementitious materials of PA heat-melt adhesive were tested. Experimental results show that PA heat-melt adhesive may contain the ability being used in self-healing techniques coupled with SMA.

Abstract: Chip seal is most frequently used as preventive maintenance (PM) treatments on asphalt pavement. However, it’s difficult to make the performance test of chip seal in laboratory. In this paper, the specimen molding method of chip seal is established in laboratory. Firstly, considering the structure and technique condition of the original pavement, a cushion layer of asphalt concrete (AC) is used as under layer of the specimen. Secondly, the construction process of chip seal is simulated in laboratory, which includes spraying emulsified asphalt and/or glass fiber, spreading aggregate, initial rolling and conservation, post-stage rolling and conservation in interval for some time. Lastly, visual inspection and sand patch test are used to evaluate the quality of the specimen. Research results show that the method of specimen molding and test in laboratory could relatively accurately simulate, evaluate and forecast the performance of the chip seal.

Abstract: Dredge materials with the water content more than 80% have been used for land reclamation in Tianjin, China. The dredge is transferred by pipeline to the reclamation place and then strengthened with the vacuum preloading technique. It has been found that with the thickness of the filled dredge layer becomes larger and larger, the quality of soil improvement is not as good as expected. Field investigation shows that after vacuum preloading the vane test strength can reach 50kPa at the ground surface, but decreases along with depth dramatically. The model test is carried out to detect the factors that may influence the efficiency of using vacuum preloading to improve dredge soil foundation. The water content, vacuum pressure and undrained strength are measured during the test.

Abstract: A large number of waste brick is hard to use among undisposed construction and demolition waste. Recycled aggregate made with waste brick was used to prepare mortar for concrete tiles in the research. Flexural strength of mortar made with both natural and recycled aggregate was studied. The influences of processing control coefficients are considered as well. The experimental results show that the use of recycled brick aggregate in concrete tiles can reach the strength requirement with suitable proportion and processing.

Abstract: The overall three-dimensional parametric model of the crankshaft has been completed based on the ANSYS Parametric Design Language (APDL) from the software of ANSYS and by combing the structure analysis capability with the statistical analysis capability of its PDS module, the reliability analysis of Monte Carlo finite element method (FEM) will be achieved according to the finite element analysis technology and the reliability basic principles. The 4110 diesel engine crankshaft was taken as an example, the parametric design will be introduced into the finite element structure analysis to implement the rapid adjustment of the structure parameter, produce the anatomic model automatically and complete the process of the structural analysis and reliability analysis. The process that the reliability analysis of the crankshaft has been realized will be described in detail. According to the results of probability analysis, the sensitivity relation between the design variable and the object variable will be obtained and at the same time the maximum stress probability distribution function of these dangerous parts and the main affective factor for object variable will be given, which will offer the useful data for the structure reliability optimization design.

Abstract: Now in China, the management of construction waste still gets less attention than it deserves. The construction waste has caused huge consumption of limited resources and led to serious environment pollution. Consequently; it makes bad effect on China's sustainable development. Firstly, the definition of construction waste is provided in the paper. Then based on the analysis of the present management situation of construction waste, different of management modes of construction waste are evaluated, and then the mode of reducing construction waste from its source is presented, which would performs well to realize the reduction and recycling of construction waste. At the same time, this paper also puts forward the construction model of carrying out corresponding countermeasures; finally, the development trend of construction model in the future is prospected.

Abstract: Consider the rubber modified asphalt preparation powder in the process of particle size, the influence factors of 40 yard, and are chosen 60 orders and class size distribution of particle size of mixed powder preparation powder, and puts forward the rubber modified asphalt mixture of different size when range, three kinds of modified asphalt compared the basic indexes and storage stability and permeable performance. Research shows that, the stability of class size distribution of the rubber modified asphalt is better than that of single particle size of the rubber modified asphalt.

Abstract: The coupling effect of flexural loading and environmental factors has great influence on the pore structures in hardened cement paste. In this paper, Mercury intrusion porosimetry (MIP) and field emission scanning electron microscope (SEM) were used to analyze and observe the changes of pore structures in hardened cement paste subjected to flexural loading and wet-dry cycles in simulated seawater. The results show that the porosity greatly increases when the flexural loading level is raised from 0 f (the ultimate flexural loading capacity) to 0.8 f. Micro-cracks are observed and the connectivity, width and density of micro-cracks increase with the increment of flexural loading. The peaks position of pore size shifts toward greater micro-pores when the flexural loading was raised from 0 f to 0.8 f. The flexural loading and simulated seawater accelerate the degradation of pore structures.

Abstract: The accelerated carbonation test was carried out for the ordinary concrete and fly ash concrete. Influences of water-cement ratio, carbonation age and fly ash content on pH value were researched. The results show that carbonation depth, including incomplete carbonized zone, can be effectively reduced by reducing water-cement ratio. So lower water-cement ratio means high performance of resistance of carbonate. The use of fly ash can optimize concrete pore morphology, it’s beneficial for anti-carbonation. However, It disadvantageous to anti-carbonation because of less carbonation material. By taking appropriate mixture of fly ash we can not only enhance the anti-carbonation ability of concrete, but also reduce the use of cement to get well economic benefits.

Abstract: Nanyang River channel regulation is one of the major projects for river comprehensive management project in Tianzhen reach of the Nanyang River. According to the geological conditions of ecological restoration, Gabion retaining wall is designed to protect the bed or banks of a stream against erosion. Gabion is made of double twisted hexagonal wire mesh, the thickness of gabion basket and mattress is 50 cm and 30 cm respectively. The slope protection work consists of two parts, the lower part is vertical wall and the upper part is slope wall. The results show that this work can solve the problem of uneven settlement and river scouring, sustain restoration of biodiversity and achieve the harmonious coexistence of humanity and nature.