The strength development caused by carbonating low heat cement mortar was compared with those of ordinary portland cement and blast-furnace slag cement mortars. The variation of the strength development of low heat cement mortar under various curing conditions was investigated. The low heat cement and blast-furnace slag cement mortars were easily carbonated than the ordinary portland cement mortar. The strength of the low heat cement mortar treated by the carbonation was higher than that of the blast-furnace slag cement mortar treated by it. However, the strength developments of these types of mortar largely varied according to the starting time and period of the carbonation reaction. The strength of mortar was measured and the distribution of pore in and the specific surface area of the hardened cement paste were studied and elucidated that the total pore volume in the hardened low heat cement was remarkably reduced and the specific surface area of it was increased by the carbonation.
