Product Overview

Conplast RP264 is a shrinkage reducing admixture (SRA) from Fosroc that addresses one of the most persistent durability problems in concrete construction — drying shrinkage cracking. When concrete dries after placement, the evaporation of water from the capillary pore structure creates surface tension forces in the remaining pore water. These forces put the hardened cement matrix under tensile stress, and since concrete is weak in tension, drying shrinkage typically results in the development of fine cracks. In restrained concrete members (such as slabs on grade, flat slab floors, and concrete on walls or beams), the restraint converts the free shrinkage into tensile stress, often causing visible cracking that compromises both the durability (by providing pathways for water and chemical ingress) and the aesthetics of the structure. Conplast RP264 works by reducing the surface tension of the water in the concrete pore system. The active molecules of RP264 adsorb at the water-air interface within the capillary pores, reducing the surface tension and therefore reducing the magnitude of the capillary tension forces that drive shrinkage. The result is a concrete with significantly lower drying shrinkage — typically 30 to 50% reduction in free drying shrinkage compared to untreated concrete at the same water-cement ratio. This reduced shrinkage directly reduces the magnitude of restrained tensile stress in restrained members, reducing the frequency and width of shrinkage cracks. Conplast RP264 is particularly valuable in large industrial floor slabs, warehouse floors, car park decks, bridge decks, and any concrete with large surface area and high restrained shrinkage risk. Space Arc Engineering distributes Conplast RP264 for industrial, commercial, and infrastructure concrete projects across Delhi NCR and Northern India.

Applications

• Industrial warehouse and logistics centre floor slabs with large unreinforced or lightly reinforced areas
• Car park deck and ramp concrete with shrinkage-induced cracking risk
• Bridge deck concrete requiring reduced cracking for long-term durability
• Retail and commercial building flat slab floors
• Pre-stressed concrete elements to reduce prestress losses from shrinkage
• Large-area ground-bearing slab concrete with long joints or jointless design

Key Advantages

• Reduces free drying shrinkage by 30–50% versus untreated concrete
• Directly reduces risk of restrained shrinkage cracking in slabs and floors
• Reduces prestress losses in pre-stressed and post-tensioned concrete
• Compatible with all Portland cements and PCE or naphthalene superplasticisers
• Can increase joint spacing in industrial floor design, reducing saw-cutting costs
• Liquid admixture for easy and accurate dosing at the batch plant