Experimental Study On The Performance Of Glazed Hollow Bead Of Recycled Concrete Columns Compression Mechanics

It is well konwn that the traditional building materials can not meet the needs of the society now, both the continuously generated construction waste and the natural gradually reducing resources content are severe challenges we are encountering now. The recycled concrete which can take advantage of the construction waste to solve the problem of environmental pollution to some extent, has attracted much attention of domestic and foreign scholars in recent years. On the other hand, the problem is in terms of building energy saving design, here are several kinds of the most common heat preservation processing methods at present, including exterior insulation, exterior wall insulation and wall-self insulation. But there are still many problems need to be solved although these methods have good heat preservation effect. In recent years, vitrified microsphere has been extensive researched as a new type thermal insulation material, mainly used to prepare the insulation mortar, After the detection of the relevant departments, it is found that No.19 of ShanXi Phoenix, built of bearing concrete, not only fully meets the design specification requirements but also meet the ShanXi local standards for building energy saving that up to 65%.Thus, to get the bearing vitrified microsphere recycled concrete with low thermal conductivity and strength that can meet the requirements of architectural design, in this article, the vitrified beads, calcined diatomite and fly ash were added into the recycled coarse aggregate concrete, functioning as modifications. Applied to the construction component, due to their coefficient of thermal conductivity is lower than that of common concrete, such concrete combined with thermal insulation block, insulation mortar can better reach the requirements of building energy efficiency, and can reduce or even avoid structure thermal bridge phenomenon. Mainly studied aspects are as follows:(1)Adjust the mixing proportion.We designed 9 group vitrified microsphere recycled concretes, each of which reach slump of 180mm and with good working performance. We did the measurement about the compressive strength, the standard thermal conductivity coffcicent and the dry apparent density of the cube separately. The experimental results showed that the thermal conductivity coffcicent and the dry apparent density reduced significantly with the mixed vitrified beads range increased from 80%-130%. Under the condition of vitrified beads mixed with the same amount, vitrified microsphere recycled concrete cube compressive strength significantly higher with the Calcined diatomite. And The combination of adding 20% fly ash and 3% calcined diatomite has the most obvious effect to promoting the vitrified microsphere recycled concrete strength.(2) Using the scanning electron microscope to observe the internal composition of vitrified microsphere recycled concrete which is already curing in a standard way. It can be seen that fly ash and calcined diatomite and alkali in the concrete material generated gelling floc can better make up for the crack in recycled coarse. This affects the bonding in all the materials. But there are a lot of broken vitrified beads scattered in concrete, it is against the strength of the concrete;(3) Select the vitrified microsphere recycled concrete which has the lower thermal conductivity and a good character to against the high compressive strength to do the column specimens compression experiments, we compare this material with the normal concrete and the recycled concrete using the data about axial compression and three kinds of characteristic load eccentricity one-way eccentric loading conditions, stress-strain relationship and compression deformation. The results show that the vitrified microsphere recycled concrete is similar with the normal concrete in the failure pattern under the axial compression and one-way eccentric loading. The vitrified beads has no impacts on the destruction mechanism of concrete, and carried out in accordance with the "regulations of technology of lightweight aggregate concrete, ultimate bearing capacity is feasible;(4) Simulated the vitrified microsphere recycled concrete column by using ANSYS software, and analysed the compression failure process, compared the ultimate bearing capacity and displacement of the simulation column with the actual test measurements. The results show that the software simulation results is good because the software simulation values and experimental values are similar.