DEVELOPING PRACTICAL SCC MIXES FOR SURFACE QUALITY AT A SMALL PRECAST CONCRETE PLANT

The use of SCC in precast concrete plant could increase rate of concrete placing, reduce labour needs, cut energy demands, extend the life of moulds, and particularly provide a much improved working environment due to the removal of vibration compaction. Such combined benefits make SCC. a very attractive option for precast concrete applications. However, for a small precast plant, there still remain, many practical difficulties/problems in producing satisfactory SCC mixes. For example, in many cases, SCC has to be produced using existing local materials and without additional powder materials, and usually with very limited production/quality controls available. Furthermore, the increase in materials cost has to be acceptable and the SCC mixes produced have the specific mix properties required for a given application.

This paper presents a study to develop practical SCC mixes using local materials and a suitable combination of admixtures at a small precast plant, and particularly to identify suitable fresh properties for the SCC mixes to achieve improved surface quality of concrete elements produced.