Testing on elastic modulus of plastic concrete

Elastic modulus of plastic concrete is studied by testing with 4 standard distance of 300mm,200mm,150mm and 100mm.The result shows that the method which is measured by computer is best,and the elastic modulus is most steady,and it is much less than that by manual record.The stress-train curve by computer record has beginning compressive bend period and longer descending period,but that by manual record has no beginning compressive bend period and has longer ascending linear period.It is presente...