Fabrication of Novel Concrete Blocks By Merging Ancient and Modern Techniques

The demand for green buildings is growing amongst rising global-level environmental concerns. Traditionally, lime was used in India as a binder. It is more durable than cement, but the strength is less. In order to improve the strength of lime based binder, many combinations of additives such as jaggery, molasses, curd, and egg yolk were used in the past, and the resultant mortar was called as lime mortar. There are many examples of the durability of lime-mortar based structures such as Mohanjo-Daro, which is a 4000-years old heritage monument of the ancient Indian civilization. Powdered burnt-brick material, termed as Surkhi, was used as ‘the aggregate’ along with jaggery.

Here, we report a combination of the ancient technique of jaggery and lime with the modern day problem of waste utilization, in which fly ash was used as the supplementary cementitious material. Jaggery solutions were prepared at different concentrations and temperatures along with lime in different ratios to set the matrix. Jaggery and sugar were both used along with lime as an additive to make pre-fabricated fly-ash blocks. These pre-fabricated blocks are environment-friendly, since these compositions can reduce the net CO₂ emission and also simultaneously utilize the fly ash, provided we wisely design the capture of CO₂ at source itself while producing lime from the limestone. Large surface areas of long-lasting buildings can provide an effective sink for the capture of CO₂ from the usual low atmospheric concentrations over centuries of such buildings’ lives.