BEHAVIOUR OF CEMENT/PLATING WASTE DERIVED PRODUCTS: UNCONFINED COMPRESSIVE STRENGTH AND SETTING TIME

摘要

The effect of the pre-treatment of plating wastes added to commercial Portland cement on the unconfined compressive strength and the setting time of the cement/waste products has been studied. The raw wastes were a sludge and a cake generated in a plating industry after the treatment of a liquid effluent by means of a physico-chemical process. From the raw waste, two pre-treated wastes were produced: a dry material obtained after thermal treatment at 105°C, grinding and sieving the raw waste; a calcined obtained after thermal treatment of the former material at 1000°C. The cement replacement ranged from 1 to 5 % dry wt of waste. The setting time of products was between 2 and 6 times higher than cement for the sludge and the dried waste products; however, the setting time of the cement/calcinated waste products was similar to that of cement. The unconfined compressive strength of cement/calcinated waste products was in the range of the cement (CEM I 42.5 R) as stated in the Spanish standard UNE 80301:96: minimum 42.5 MPa and maximum 62.5 MPa. However, the cement/sludge products only fulfilled the limits for products containing 1 % waste.