*Paper presented by S. K. Jain and K. M. Maheshwari, Design and Planning Directorate, Riband Dam Irrigation Department, Uttar Pradesh, at the 27th Annual Meeting of the Research Committee, July 1957.
This paper outlines the various types of admixtures used to improve the workability of cement-concrete mixes, and discusses the relative merits and economics of air entraining agents versus wetting agents. A brief account of laboratory experiments performed in the Rihand Research. Laboratory on the different admixtures has been given. For sites where durability and resistance against freezing and thawing are not the criterion for the use of air entrainment in concrete mixes, the optimum percentage of air has been worked out purely on considerations of workability and economy. The paper also presents the experimental data of an air entraining agent, viz., Rihand AEA, developed from indigenous products at the Rihand Research Laboratory which compares favourably with the accepted air entraining agents in respect of efficiency whereas the cost of this admixture used in concrete for the same air entrainment is comparatively much lower than that of any other proprietary air entraining agent.
