Title:
Research on Concrete in Hot Environments at the National Building Research Institute, Haifa, Israel
Author(s):
D. Ravina and I. Soroka
Publication:
Symposium Paper
Volume:
139
Issue:
Appears on pages(s):
107-130
Keywords:
admixtures; corrosion; cracking (fracturing); creep properties; drying shrinkage; environments; fly ash; hot weather construction; plastic shrinkage; retempering; slump; strength; workability; Materials Research
DOI:
10.14359/3900
Date:
9/1/1993
Abstract:
Specific problems associated with concrete and concreting in hot, particularly hot-dry, weather, have been recognized in Israel since the late 1950s. The effects of hot environments on properties and performance of concrete have been studied for 35 years at Israel's National Building Research Institute. This research has included laboratory tests as well as site experiments conducted in hot-dry and hot-wet climate regions, some of which were in marine environments. The effect of environmental factors on concrete properties has been studied for both fresh and hardened concrete. Studies related to fresh concrete dealt with climatic effects on water demand and slump loss in concretes with and without admixtures, and in concretes incorporating fly ash. Special attention has been given to workability and slump loss of concrete subjected to long hauling and mixing periods. The mechanism of plastic shrinkage and the factors affecting possible plastic shrinkage cracking have been extensively investigated. Studies on properties of hardened concrete include early and later age strength, drying shrinkage, and creep, and how these factors relate to the very early exposure of fresh concrete to hot environments has been investigated. The effect of hot environments on reinforcement corrosion has been studied both in the laboratory and in exposure sites.