Senior chemical engineer, Wiss, Janney, Elstner and Associates Inc., Northbrook, Ill.
The determination of cement content of hardened concrete using the maleic acid (MMA) extraction method was evaluated using laboratory-prepared samples. The effect of variations in the strength of the maleic acid solution and sample digestion time were evaluated. The method was found to be very accurate. The difference between the actual and determined cement contents of the laboratory-prepared concretes ranged from 0.0 to 0.3 bags per yd3 with an average of 0.2 bags per yd3. A test procedure for using the method to determine the cement content in concrete cores is proposed. The method is recommended as an adjunct to petrographic examination, since significant errors may occur if the cement paste is extensively carbonated, if such admixtures or aggregates as fly ash or slag are present, or if the aggregates contain carbonate minerals.
Paper ID: CCA10210J