An increasing number of projects are considering precast concrete in their construction, encouraged by its cost and time savings, as well as its superior quality.
Precast systems are growing in popularity worldwide because of their improved versatility, efficiency and resilience compared with traditional cast-in-situ building methods. Precast concrete standardised structural components are often produced to PCI (Precast or Prestressed Concrete Institute) specifications using admixtures such as ADVA Cast - a plant-added superplasticiser formulated for precast or prestressed concrete and a leading product in the Indian market from GCP Applied Technologies. 'Contractors primarily like the speed advantages that precast offers, but it's also important not to compromise quality or costs,' says Dr Jiang Jia Biao, Specialty Product Manager, GCP Applied Technologies. He adds, 'Prefabricated systems break the quality-speed compromise.'
Breakthrough in speed, quality and eco-friendliness
With precast systems, as the structural components are manufactured off site; excavation, footings and foundations can be constructed while modular units are being produced in the plants. With no formwork assembly or concrete pumping needed at height, precast solutions mean fewer people working at the top of a building, which is both cheaper and safer.
In order to achieve the required compressive strength to remove precast elements from their forms the the day after casting; a high degree of quality control is necessary. This not only results in high early strength, but an increase in other hardened properties such as long-term strength and lower permeability, which results in better long-term durability. 'GCP's ADVA Cast admixtures is formulated to deliver improved workability in concrete and higher early-stage compressive strength. It also gives a superior finish to surfaces and better overall air entrainment control,' says Biao.
Precast construction systems also minimise the footprint of a project site in terms of waste and neighbourhood disturbances. And, with minimum work on site, it also reduces noise and dust pollution.
Advanced precast admixture
ADVA Cast from GCP Applied Technologies is widely-recognised as one of the world's leading admixtures for prefabricated construction. Its design includes a high efficiency, low addition rate polycarboxylate-based high-range water reducer. Compared to other precast products, it offers enhanced concrete cohesiveness with low viscosity for rapid placement. Even in low water-cementitious ratio applications, ADVA Cast can also impart high workability without segregation in the concrete. It meets the requirements of ASTM C494 as a Type A and F, and ASTM C1017 Type I plasticising. It is supplied as a ready-to-use liquid that weighs approximately (1.1 kg per litre). It does not contain any intentionally added chlorides.
A proven track record
GCP Applied Technology has supported the development of a large number of precast concrete developments around the world. They include the Second Penang Bridge in Malaysia, public housing in Singapore, subway tunnel segments in Singapore and China, and the Broad Museum and the James F Battin US Federal Courthouse in the US. In addition to providing admixtures that improve the quality of concrete, GCP Applied Technologies, a PCI Premier Partner, works closely with its clients to tailor its solutions to meet the needs of individual projects. ADVA Cast is compatible with most GCP admixtures as long as they are added separately to the concrete mix. GCP has a network of dedicated precast concrete specialists, expert technical services team and advanced laboratories in India to help our customers achieve greater construction efficiency and quality.
(Communication by the management of the company)