Title:
Early Structure Formation in Concrete with Water-to-Cement Ratio 0.2
Author(s):
Ivan Sitnikov and Vasily Sitnikov
Publication:
Symposium Paper
Volume:
326
Issue:
Appears on pages(s):
116.1-116.8
Keywords:
durability, ultra-high-performance concrete, water-cement ratio, early stage hardening, cement stone, ettringite, cement hydration
DOI:
10.14359/51711099
Date:
8/10/2018
Abstract:
Concrete with w/c ratio of 0.2 and lower is indeed material of a new generation. Its properties significantly surpass such of regular concrete grades in large due to the absence of mixing water not actively involved in the physical-chemical processes of cement hydration. In a sense, w/c ratio of 0.2 signifies a threshold in the material science of concrete that no research did reach before 1990s. To move this realm even further, we have been aiming at producing UHPC that crosses this threshold we felt a necessity to define a basic phenomenology of such concrete hardening, especially on the early stages. Our analysis of the kinetics of the strength gain provides that this concrete gains its main physical-mechanical properties after 7 days, and its compressive strength exceeds 100 MPa (14 500 psi) already after 24 hours in normal conditions. At last, this type of UHPC is economically viable due to a relatively low content of cement (500kg/m3 (31.2 pcf)), the use of ordinary fine aggregate, and a possibility of using standard batching equipment in the production.