Research On High Performance Lightweight Aggregate Concrete (HPLC) And Its Application

High performance lightweight aggregate concrete (HPLC) is a kind of lightweight environment-protected building material with high strength, good workability, volume stability and durability, which suits for large scale engineering such as high buildings and bridges and some important engineering which had a complicated geography condition or a special command for durability. In the paper based on the study of mechanical property, durability, microstructure, engineering applying and theory of designation of HPLC, the relation among the composition, structure and performance of IIPLC, which is an essential theoretical base of HPLC, is discovered. The main research work and compliments of this paper are:The concept on HPLC is newly described from the aspect of development strategy, economic, demanding of technology of material. Based on the analysis of the destroy theory and the research of property of the composition and structure of HPLC, the ideology of designation of HPLC, and the theory of interface strengthening and strength suiting are built; The new method of designation of HPLC which is based on the condition that the mixture has a high stability is invented; a math modal is built to direct the designation of HPLC.Under the direction of such theories, the influence of the composition of the concrete to the workability, mechanical property and durability of HPLC is analyzed systematically; the key technology of the preparation of HPLC was grasped. The theory of strength improvement of subsidiary bonder is detected, special additive-FDL for HPLC is made, LC40-LC60 HPLC with the slump over 18cm, the slump flow over 50cm, segregation degree below 5%, small drying shrinkage, high tension strength and long durability is prepared. The concept and experimental method of the segregation degree of the mixture is put out and the analytical system of high performance HPLC is built.The hydration theory and the structure forming of HPLC are analyzed through XRD, SEM, EDXA, and the analysis of pore structure, micro hardness. The model of the interface structure between lightweight aggregate and harden cement paste is divided into 4steps, which are penetrating, hydrating and hardening, diffusing of moisture and ion, forming of optimal interface structure, and the ideal structure model of lightweight aggregate is built. Based on the two models, the optimal structure model, which sets an important basis for the designation, preparation and produce of HPLC, is constructed.The key technologies, such as mixing, such as mixing, transportation, pumping, curing, etc. for engineering application of HPLC are analyzed systematically; the program of the designation of HPLC was made out and the quality control method is put out. The LC40 HPLC and its engineering technology was applied to Caidian Hanjiang Bridge, which successfully solved the shortages of HPLC, such as poor pumping ability, lacking of volume stability. The HPLC was pumped firstly in China (over 100m in height and 250m in length), which gives an essential support for the produce and application of HPLC.