Environmental implications of stubble and their usages as soil and concrete reinforcement

Abstract

Stubble burning has been reckoned among the major contributors to air pollution, especially in North India. It is a significant source of gaseous pollutants causing serious damage to human health and the environment. The situation is more hazardous due to the intensive rice-wheat rotation system which generates a large amount of stubble with no significant use as good as burning due to poor knowledge of the management of stubble. It was estimated that about 352Mt of stubble is generated each year in India, out of which 22% and 34% are contributed by wheat and rice stubble respectively. The behavior of randomly distributed dry stubble- reinforced soil and concrete has been extensively studied in recent decades. Shear strength of soil and concrete has shown a very positive impact on reinforcing with stubble which is easily available in mass. The study seeks to investigate the effect of random inclusion of stubble on the liquid limit, plastic limit, optimum moisture content, maximum dry density, and compressive strength of soil and concrete. The stubble content variation used is 0%, 0.1%, 0.3%, 0.5%, 0.7% of the dry weight of the mixture. The results show that reinforcement of stubble can increase cohesion, friction angle, and shear strength with a notable decrease in the permeability of the soil and its plasticity. The study recommends that the addition of stubble should be made for the improvement in physical and mechanical properties of soil and concrete but quantity of stubble and other related quantities must be adequately metered in the production process.