Polycarboxylates ( PCE )
Bisley supplies Polycarboxylate ( PCE ) in both liquid and powder forms. PCE superplasticiser is a high molecular weight surfactant polymer for use in cementitious systems. It has adsorption characteristics similar to conventional water reducers such as sulphonated naphthalene, rendering a charge to its surface ( leading to mutual repulsion) , and also steric hindrance from branched chains ( enhancing dispersion ). There are several PCE versions which are quite specific in their actions. These can be blended together to create a “custom performance mix”.
- Slump Retention Grade
- Water Retention Grade
- Accelerating Grade
- Defoamer Grade
Polycarboxylate superplasticisers offer superior performance in dispersing cement particles at smaller dosages, and retaining concrete slump without prolonging setting times.
During the last few decades, the use of both mineral admixtures ( fly ash, silica fume, blast-furnace slag ) and chemical admixtures (retarders, accelerator, water reducers and superplasticisers ) by the construction industry has increased substantially. Mineral and chemical admixtures play an important role in changing the physical and chemical properties of concrete matrix. As with other superplasticisers, the use of PCE’s reduces the water requirement for a given slump. The water reduction in samples containing silica fume is higher than that of the plain OPC paste. Typically water reduction ranges between 10-30 % for OPC mixes and 15-35% OPC/SF mixes. The reduction in required water with SF mixes arises from the dispersion mechanism of PCE on both the cement grains and SF particles.