This paper presents the results of a study on the effects of powdered aluminium as an ingredient upon the air content, flowability and strength of prepacked concrete mortar and upon the compressive strength of prepacked concrete. From the results, it may be observed that employment of the optimum amount of powdered aluminium as an ingredient of prepacked concrete mortar scarcely affects the flowability of mortar but improves its compressive strength as well as that of prepacked concrete. The optimum amount is found between 0.01 and 0.02 percent of cement and pozzolanic material by weight.