THỰC NGHIỆM DÙNG LƯU BIẾN KẾ THEO DÕI SỰ BIẾN THIÊN CÁC THÔNG SỐ ĐỘ NHỚT, NGƯỠNG CHẢY CỦA VỮA BÊ-TÔNG TÍNH NĂNG CAO

In this paper, authors present the experimental studies of rheological properties of high performance concrete. In general, rheological properties including viscosity and yeild stress report the workability of concrete material after mixing step. Authors used a coaxial with vane type rheometer in laboratory to measure the rotational moment of the prepared HPC material. Obtained results showed the compressive strength of such HPC around 120 MPa after 28 days of curing period. Measured vicosity and yeild stress increases over time in the period of 0-100 minutes. 70 minutes after mixing, the studied mixture of HPC lost the workability considering the large variation of both vicosity and yeild stress values.