Research On The Modification Of Foam Concrete

Cement foam concrete has good performance of thermal insulation, fire-resistant and lightweight was widely used in the market, however the cement foam concrete hardens slowly, specimen molding and stripping are difficult; its compressive strength is too low to meet the requirements of the building structure; high water absorption, poor frost and weather resistance, limiting the large-scale promotion of foam concrete.In this paper, use of calcium chloride, lithium carbonate and other additives to promote the setting and hardening of cement foam concrete, promote the mechanical properties through silica fume,Latex,etc. use of latex, styrene-acrylic emulsion to reduce water absorption and improve the frost and weathering performance of foam concrete for these problems, on this basis, research on the thermal conductivity and other properties. research shows:(1) Calcium chloride have significant role in promoting setting and hardening properties of cement foam concrete, tests showed that when the incorporation of calcium chloride 2%,the initial setting time was 14 hours and final setting time was 25 hours, respectively compared with undoped kind shortened by 11 hours,7 days compressive strength of cement foam concrete up to 2.2MPa, increased 0.8 MPa.(2) Silica fume and styrene-butadiene latex had good composite effect,when the incorporation of 8% latex,6% silica fume, the 7 days compressive strength of cement foam concrete was 2.5MPa, increased 1.1MPa,28 day compressive strength of cement foam concrete was 2.9MPa, increased 1.2MPa, the effect of modification is significant.(3) Latex and silica fume had significant compounding effect for improving frost and weathering performance composite effect of the cement foam concrete, when the incorporation of 6% silica fume,12%Latex, water absorption of cement foam concrete was 46%, compared with undoped samples were reduced by 19%,the number of freeze-thaw cycle 22 times, increased eight times than the non-doped samples.(4) Incorporation of latex and fly ash in concrete can improve the insulation performance, when incorporate 8%styrene-butadiene latex and more than 30% fly ash, insulation performance of concrete foam is better.