Experimental Study On Mechanical Properties Of Thermal Insulation Glazed Hollow Beads Concrete Mixed With Coal Gangue

As an additional product in the process of coal mining,coal gangue is a kind of material whose strength is between the coal and the natural stone.If can not be used effectively,coal gangue will not only take up a large amount of land resources,but also bring a certain degree of influence on the surrounding water resources and atmospheric environment.Using coal gangue as an aggregate of concrete is a kind of effective way to utilize coal gangue;In this paper,the research subject is based on the current China and the world’s advocacy of energy saving,green and environmental protection concept.The coal gangue mixed with thermal insulation glazed hollow beads concrete(hereinafter referred to as TIC)as a coarse aggregate in concrete,successfully prepared for this new type of green building material—thermal insulation glazed hollow beads concrete mixed with coal gangue(hereinafter referred to as CGTIC)whose strength grade can reach C30~C45,thermal conductivity is 0.4978~0.7840W/(m·K).As a completely new building material,thermal insulation glazed hollow beads concrete mixed with coal gangue’s various features and performance is not known yet.Therefore,this paper mainly explores CGTIC’s basic mechanical properties including the cubic compressive strength,axial compressive strength,static compression elastic modulus,flexural strength and splitting tensile strength in experiment by referring to the standard test methods of mechanical properties of ordinary concrete(GB/T 50081-2002).Specific research works carried out as follows:(1)CGTIC’s mix proportion were designed by reffering to the ordinary concrete and TIC.And through a series of trial and distribution process,the concrete which conforms to the expected standard is formulated,and the mix proportion of 5 different kinds of coal gangue mixture’s CGTIC is determined.(2)In this paper,the basic mechanical properties of 5 different kinds of coal gangue mixture’s CGTIC were studied.It is found that CGTIC’s failure modes and failure mechanisms vary widely both between the ordinary concrete and TIC.The failure of CGTIC under external loads occurs not only in the traditional weak area—on the contact surface between the coarse aggregate and the cement colloid,the coarse aggregate of coal gangue itself has also been destroyed at the same time.(3)On the basis of the basic mechanical properties’ experiment,the influence regularity of coal gangue’s mixing amount on the various properties of CGTIC and the transformation rules of cubic compressive strength with age were studied.The results showed that the basic mechanical properties of CGTIC decrease to different extent with the increase of coal gangue’s mixing amount.This is mainly caused by the low strength of coal gangue,the development of joints,the needle plate content and so on.The effect of coal gangue’s mixing amount on the splitting tensile strength is the most significant.With the increase of age,the transformation rule of the cube compressive strength presents the law of the first fast and slow development,and it has little relation with the coal gangue mixing aount;and CGTIC belongs to the early strength concrete.(4)The finite element software ANSYS was used to simulate the CGTIC frame structure under static load.It is found that CGTIC can not only reduce the weight of the structure,improve the safety performance of the structure,but also reduce the stress in the structure and reduce the reinforcement ratio.(5)Besides that,the direct economic benefits,social benefits and environmental benefits of CGTIC were analyzed in this paper.The results show that CGTIC is not only feasible in practical construction projects,but also has significant benefits in many aspects.