Experimental Study Of Self-compacting Lightweight Concrete

Concrete is a kind of building material which is used broadly in the field of civil engineering at present.This material has been improved fast since the initiation of normal concrete.Increasing novel High performance concrete(HPC) has been discovered by changing the compositions in concrete.Self-compacting lightweight concrete(SCLC) has accepted as a concept of HPC.It is developed on the basis of ordinary self-compacting concrete(see) and Lightweight Concrete(LWC).Self-compacting lightweight concrete(SCLC) has all the good performance of both SCC and LWC,including smaller density,higher compressive strength,excellent workability (fluidity and filling-up-space) and relatively higher elastic modulus.SCLC has improved the adverse properties of SCC and LWC simultaneously,so a new field is exploited for the development of concrete.SCLC is a favorable building material for application in structural design,repair and maintenance of old concrete structures,and therefore a trend of application will be seen in field of structure engineering.Self-compacting lightweight concrete(SCLC) was invented after 2000.The research and practical application of SCLC is still at the initial stage.The information on the properties of SCLC is relatively scarce,which restrict the future application of SCLC.Mix proportions for Self-compacting lightweight concretes(SCLC40 and SCLC50) were tested according to the formulas of the water content of overall calculation method and fixed volume content of aggregate method.On the basis of the parameters of flowing diameter and L-Box,optimal mix proportions for SCLC40 and SCLC50 were discovered in this experiment. Workability of fresh SCLC,the principal mechanical properties of SCLC and the durability performance are tested,including Slump Flow,J-Ring,U-Box,L-Box,V-Funnel,Column segregation,compression strength,cleavage extension strength,creasing resistance,elastic ratio,free shrinkage and creep respectively.In addition,a comparison between SCLC and common concrete is conducted.The results of test show that the workability of Self-compacting lightweight concrete (SCLC40 and SCLC50) match standard of EFNARC.The SCLC shows many advantages, such as higher compression strength/density,better tenacity and smaller static elastic ratio and so on.The free shrinkage and creep for Self-compacting lightweight concrete mostly develop in the early month,especially a month during removal of shuttering and load-on.The speed rate of free shrinkage and creep is getting slower and slower.The shrinkage rate of Self-compacting lightweight concrete at early stage is lower than that of ordinary self-compacting concrete,while the final shrinkage speed rate is higher than that of elf-compacting concert.The creep coefficient of SCLC is smaller than that of SCC.This research provides reference for the project application of SCLC.