Study Of Properties Of Physical And Mechanical With Supplementary Repairing Materials To Recycled Coarse Aggregate Concrete

Along with the accelerating of the refurbishment of the old city-Yinchuan, urban construction waste increases rapidly. In order to achieve sustainable and green development of construction industry. This article will focus on the separation of construction waste, especially on the reproduction of coarse aggregate by wasted concrete, considering the high percentage of ash waste and residue among industrial waste in Ningxia, put the supplementary material of fly ash, mineral powder into cement will reduce the consumption of cement,and adding the new air-entraining agent sodium lauryl sulfate K12 to improve the performance of recycled concrete.So as to realize the coordinated development of the environment and resources. This article is based on a basic study, focusing on a systematical study on basic physical and chemical properties of recycled coarse aggregate in Yinchuan, in order to select the optimal mix of renewable coarse aggregate concrete, make a conclusion on the effect of common environment factors caused to the damage on the durability of concrete, make an experimental study on the the model set up for the programs. In addition, set up a model of damaged recycled aggregate concrete under uniaxial stress according to damage theory. Finally, make suggestions and measurements on the effective utilization of construction waste in Ningxia.The main contents include:First, this dissertation conducted a deep investigations into domestic and foreign research situation of the recycled concrete, the future trends, and construction waste separation, crushing process, classification standards, metrics, etc.. On the basis of the study mentioned above, this dissertation puts forward the suitable applicable technical and their standards; in Yinchuan region,selects the representations of the removal of old buildings typical beams, the abandoned laboratory test block as coarse aggregate material to do a specific basic performance test and made a systematic analysis, also proposed in this study using artificial separation of recycled coarse aggregate crushing combination of physical ways to strengthen the way water rinse, the second mixing process and chemically enhanced way to add an anionic surfactant to improve the recycled concrete performance, anionic surfactants Use agent K12 alkyl sulfate part of this research and innovation, studies show it to improve further freeze-thaw durability of recycled concrete damage, impermeability in a better way.Followed, this dissertation selected the ratio of water-cement, coarse aggregate, fly ash, slag ash five factors and four levels of orthogonal pilot program,by testing the slump recycled coarse aggregate concrete cube compressive strength, analyzing how the different contents influences the natural regeneration aggregate concrete slump, compressive, affect performance, by this way to obtain the appropriate mix ratio, the high compressive strength, considering for A2B2C3D2E3, namely water-cement ratio of 0.32, which contents 40% recycled coarse aggregate,20% ash content,10% slag content. The main factors to select the degree of importance as follows:Water-cement ratio of recycled coarse aggregate ash, slag, fly ash. Experimental results show that recycled coarse aggregate concrete mechanical properties such as compressive strength, splitting tensile strength, elastic modulus are all lower than natural aggregate concrete which has the equal strength. And due to the presence of high water absorption of recycled coarse aggregate, during the mixing proceeding, the quanting-water demanding is greater than the natural aggregate concrete.Then puts the model of the common environmental factors on the durability of recycled concrete damage, taking the model as example,f,tested all the groups impermeability of concrete, erosion and abrasion resistance, resistance to sulfate attack, contractile properties, freeze-thaw cycle performance, anti-carbonation properties in the study. On the basis of the experiment, made a systematic, comparative analysis and evaluation of recycled concrete’s performance. On the basis of recycled concrete damage model which obtained experimentally:the recycled coarse aggregate concrete’s impermeability can fulfill the P10 requirements, the erosion and abrasion resistance of concrete can meet the general requirements of the project against the punch wear, and the shrinkage is slightly larger than the normal concrete shrinkage, the ability of resist the acid sulfate is better able to meet the requirements of ordinary concrete impermeability, freeze-thaw cycle performance is significantly lower than that of ordinary concrete;adding K12 alkyl can significantly improve the entraining agent’s recycled concrete frost and impermeability,it can also appropriate increase the erosion and abrasion resistance.Followed by scanning electron microscopy aggregate, recycled concrete cement interface microstructure morphology and interfacial transition zone to test, analyze microscopic composition, interface characteristics, injury characteristics, from the micro-level view to study fly ash, slag, K12 alkyl sulfate of recycled concrete aggregate-cement interface to improve the situation, and were compared with natural aggregate concrete.Looking for the damage constitutive relations of the recycled coarse aggregate concrete is the key issues of the paper studied the damage theory, the basic principles of thermodynamics, and analyzed the evolution of damage done different. On this basis, mentioning damage constitutive model which is under uniaxial stress,by analyzing and comparing the differences between the model and the experiments, indicating that the model in the uniaxial compression test stress-strain curve rise can simulate the force recycled aggregate concrete under uniaxial stress conditions-strain relationship, there are certain segments offset decline, which needs to make a further research.Finally, this dissertation made a simple technology assessment of the construction waste comprehensive and effective treatment and effective utilization of recycled coarse aggregate system, and came up with the effective way to solve the problem from a theoretical point of view.