The Development And Application Technology Of Precast Lightweight Aggregate Concrete Insulation External Wall

Precast concrete sandwich insulation wall(PXSIW)is a new type of precast concrete wall,which performs well both in structural bearing and energy saving.This kind of shear wall is composed of the connectors,insulating layers and internal and external concrete walls.This kind of wall has the features of prefabricated production,good thermal insulation,which is a green,environmentally friendly new type of precast wall form.Although the advantages of the wall are outstanding,the features of large dead-weight have also limited the development of this technology.Under the financial support provided by Jiangsu key R&D plan(forward-looking industry and common key rechnologies),this paper applies high-performance lightweight aggregate concrete(LWAC)technology to the precast sandwich insulation wall.And on this basis,the static performance and thermal performance of precast sandwich insulation wall were performed,and preliminary construction suggestions were given.The contributions of this thesis mainly contain the following:1.Systematic tests and analysises were conducted to the properties of concrete raw materials.The mix ratio was designed in method of semi-empirical and semi-theory way.The optimization design was carried out through the orthogonal experiment,and the optimal mix proportion was obtained by the function method.2.LWAC were designed with core-shell and burning-free lightweight aggregate,different fine aggregate(fly ash clay sand and power plant residue)and amount of air-entraining agent,which have good work performance,the compressive strength 30MPa,dry apparent density1500Kg/m~3.The performance of concrete was also studied.It can be seen that when the content of clay sand reaches 25%,LWAC exhibits an ideal light-weight high-strength characteristic,and can also improve its drying shrinkage and thermal conductivity.3.Three PCSIW and two solid wall panels with two simple supports ends were tested under monotonic loading.The results showed that the displacement ductility coefficient of specimens was between 3.8 and 5.All of them showed good ductility characteristics.Lightweight aggregate concrete and ordinary concrete had different crack development and distribution status.The flexural rigidity and load capacity of LWAC were lower than those of ordinary concrete components.The sandwich insulation wall with the headed steel-GFRP composite connector(HSGC)has good combination performance;At the same time,the finite element software ABAQUS was used to analyze the loading process of the prefabricated sandwich insulation wall under the plane load.The finite element results were in good agreement with the experimental results.4.Thermal performance test was conducted to One PCSIW and one solid wall panels.The calculation of the thermal index shows that the XPS insulation layer is the key component to improve the insulation performance of PCSIW,and the heat transfer coefficient of LWAC wall panel is about 31.68%of the ordinary concrete wall.The LWAC has superior thermal performance.Through the detection of the thermal performance of the wallboard,the heat transfer coefficient of LWAC sandwich wallboard was 0.86,and the thermal inertia index was1.66,which met the thermal specifications of related specifications.Finally,preliminary suggestions were made for the preparation of lightweight aggregate concrete,the manufacturing process and so on.