Abstract
In massive concrete structures thermal cracks are caused by external restraints in the vicinity of construction joints between old concrete and new one. This paper discusses the results of investigation performed to reduce such a thermal stress, by placing a layer of extraordinarily set-retarded concrete between them. Experimental study was carried out by changing the dosage of setting retarder for four long specimens. It is indicated from the study how to prevent such thermal cracks with the proposed construction method.
