HYGROSCOPIC MATERIAL, METHOD FOR PRODUCING THE SAME, AND CONCRETE SLUDGE FOR WATER RETENTION AGENT

PROBLEM TO BE SOLVED: To supply a hygroscopic material which has a high moisture absorbing/humidity conditioning capacity and prevents absorbed water from leaking at a low price.SOLUTION: A hygroscopic material includes a deliquescent inorganic salt and a water retention agent which absorbs a deliquescence liquid generated by the moisture absorption of the deliquescent inorganic salt. The water retention agent is a hygroscopic material which is concrete sludge. Since the performance and price of a desiccant using deliquescent inorganic salts including calcium chloride are decided depending on the water retention agent storing the deliquescence liquid, concrete sludge which is subjected to disposal is used for the water retention agent to reduce costs.