| Title |
Design of Mix Proportion for Concrete with Crushed Sand by Very Fine Sand and Particle Shape |
| Abstract |
This study is aimed for investigating the design of mix proportion for Concrete with crushed sand by Very Fine Sand(Finer than 75 m) and particle shape(Shape Index ; solid content ratio of sand particles passing 2.5mm and retained on 1.2mm sieve). The tests were conducted on mix proportion of concrete having a constant slump(15+-1cm) and air content(4.5+-1%) respectively and the experimental factors and numerical values for estimating water demend in unit volume were 0%, 3.5%, 7% in VFS ratio and 52%, 54%, 56% including 58% with river sand in Shape Index.The results indicated that water demand was increased with increasing ratio of VFS replacement and decreasing Shape Index. On the other hand, optimal sand aggregate ratio without segregation was decreased with increasing ratio of VFS and decreasing Shape Index. However, compressive strength of concrete with crushed sand was generally higher than the concrete with river sand without regard to VFS and particle shape. The modified formulars by multiple regression analysis based on several results of experiment are as follows; = 211.177C/W+2.917Si-1.857Vfs-223.2(R2=0.9518), W = -5.417Si+1.857Vfs+480.8(R2=0.9857),S/A= 0.417Si-0.333Vfs+21.56(R2=0.9782) |