Study on preparation and key performance of C35 machine-made sand pavement concrete in Foshan first ring road

Abstract

In this section, the influences of water-binder ratio, the total amount of cementitious materials, sand ratio, and different fly ash content on the long-term performance and durability of C35 machine-made sand pavement concrete, such as workability, mechanical properties, electric flux, dry shrinkage, early crack resistance and so on, are studied. It is found that when the water-binder ratio is 0.37, the total amount of cementitious materials is 382 kg/m3, the sand ratio is 37%, and the fly ash content is 15%. The performance indexes of concrete are as follows: the 7-d compressive strength is 37.2 MPa, the 28-day compressive strength is 46.6 MPa, the flexural strength is 5.3 MPa, and the elastic modulus is 32.6 Gpa. The 28 d shrinkage rate is 283ⅹ10-6, the total cracking area per unit area is 664 mm2/m2, and the 56 d electric flux is 1415 C. The slump is 215 mm, the expansion degree is 550 mm, and the emptying time of the inverted slump cone is 12 s.