ABSTRACT
Radical Concrete Technology. Edited by R K Dhir and P C Hewlett. Published in 1996 by E & FN Spon, 2-6 Boundary Row, London SE1 8HN, UK. ISBN 0 419 21480 1. ABSTRACT. Polymethyl methacrylate (PMMA) mortars are prepared with the proper binder formulations and mix proportions to have working lives of 30±5 minutes underwater and in air at temperatures of 0, 10, 20 and 30°C, and tested for flexural and compressive strengths and adhesion in flexure. From the test results, the effects of water temperatures in underwater placing or bonding and curing processes on the strength and adhesion of PMMA mortars are discussed. It is concluded from the test results that the use of PMMA mortars underwater in the water temperature range of 0 to 30°C is recommended for practical underwater construction work. Keywords: Polymethyl Methacrylate Mortar (PMMA), Flexural Strength, Compressive Strength, Adhesion in Flexure, Water Temperature, Underwater Placing or Bonding. Dr M.A.R.Bhutta received Ph.D. from Nihon University in Koriyama, Japan, and is a Research Engineer at Maeta Concrete Industry Ltd., Sakata, Japan. Dr Y.Ohama is a Professor of Architecture at the College of Engineering, Nihon University, Koriyama, Japan. He has been involved in the research and development of concrete-polymer composites for more than thirty-five years. Dr K.Demura is an Associate Professor of Architecture at the College of Engineering, Nihon University, Koriyama, Japan. His main interest has been in the research and development of concrete-polymer composites. Mr N.Maeda is the President of Maeta Concrete Industry Ltd., Sakata, Japan. His research interests include precast concrete products, MDF cement and polymer concrete.
INTRODUCTION Polymethyl methacrylate (PMMA) mortar and concrete are normally made by mixing methyl methacrylate monomer-based binders with dried aggregates and polymerizing methyl methacrylate under proper curing conditions, and their properties are temperaturedependent because of the thermoplasticity of polymethyl methacrylate in the hardened mortar and concrete [1-3]. This fact also is a very important point to be considered in the underwater placing or bonding of PMMA mortar and concrete. Therefore, some investigations must be conducted to examine the effects of water temperatures in underwater placing or bonding and curing processes on the properties of PMMA mortar
