High Strength Foam Concrete Research

As a kind of porous lightweight materials, foamed concrete is widely used in building energy efficiency and reducing loads of structure and foundation displacement backfilling and so on,has various kinds of excellent performance such as heat insulation,sound insulation and seismic energy absorption etc.But it is due to introducing a large volume of air bubbles,the strength of foam concrete is generally lower than normal concrete’s,which limit its application fields. How to improve the strength of foam concrete has become the mission of research workers.This experiment mainly discussed the methods of improving matrix strength of foam concrete.We choose common three kinds of mineral admixture to research the best proportion of the mixed by orthogonal test.Moreover,this paper researched the influence of sand-binder ratio,water binder ratio, curing conditions and age on the strength of foam concrete,and also researched the way of improving pore structure of foam concrete by adding light weight ceramisite to the mixed.The results of the study show that:there is a best mixing ratio of mineral admixtures,using that could reduce the cement content per cube,improve the utilization ratio of industrial waste residues,as well as could improve the workability and strength of foam concrete.According to the experiment,the effect of particle size of quartz sand distribution on strength of foam concrete is verry big,and the fine the size of quartz sand is,the smaller the strength of foam concrete decreased.And at low density,the lower the water-binder ratio,the higher the strength of foam concrete.In addition,high strength foam concrete generally need to keep in standard curing condition for 28 days,if it adopt heat water curing,the later strength will be higher,and the strength increased with the age grew.At last, by adding light weight ceramisite to the mixed, the pore structure of foam concrete was improved greatly,and the compressive strength reach up to 39.1MPa according to that proportion when the dry density of foam concrete is 1326kg/m3.Another reseach has been taken in this paper is that the factors influence the flexural strength and elastic modulus of foam concrete.According to the test,the flexural strength of foam concrete only improve a little,or even no increased when the strength reach a certain degree because of the existence of porosity.The factors influence the elastic modulus of foam concrete is same as that of common concrete,and with the water binder ratio reduced, elastic modulus of foam concrete increased gradually.If mixed with high elastic modulus aggregate, elastic modulus of foam concrete will increase as well.