The natural biopolymers from plants and natural sources have been used in with the construction materials during the historic and pre historic period world over and many of these structures are even today rare in good shape confirming the durability of these structures which used natural biopolymers, vegetables, selected plant & fruit extracts.
These natural biopolymers are organic materials available from selected plants, seeds, fruit extracts which are chemically carbohydrates, proteins, oils and fats and their derived and hydrolysed products, plant latexes, gums starches and natural carboxylic acids / esters and their salts and even blood (animal ), milk and eggs, which had properties similar to the present day synthetic admixtures in terms of reducing the water content of the binding materials, which accelerates the hardening processes of the binders providing water retentivity, renderability and compaction desirable to produce a durable compacted hardened structure as desired to bind the stones and aggregates used in these historic and prehistoric structures .
These natural biopolymeric additives / admixtures improve the properties of construction material formulations (i.e mortars, plasters mixes used) in fresh (green) as well as in hardened state and also improved the resistance of the structures to the deterioration processes in nature thereby enhancing the durability of the structures, these biopolymeric additions also exhibited biocidal and insecticidal properties leading to resistance of the constructed structure to bio-corrosion as well as termite resistance.
Many of these usage of biopolymers, in the ancient period were used according to their local availability and compatibility with local construction materials and due to lack of sharing and lesser communicational possibility these expertise wither disappeared or some of these in small percentages are still practiced in rural constructions by the knowledge passed from one generation to another (hereditary).
The paper attempts to review the different types of the available natural biopolymers and the effects of these additions on the fresh and hardened properties of Mortar and Concrete.
The paper further discusses the experimental data generated at the author’s laboratory as a part of exploratory work carried out, on use of natural polymers and its impact on the properties of Cements, mortars and concretes in terms of increased early strengths, Air entraining effect, better Adhesiveness, Anti microbiological agent, improvement in plasticity & workability of the mortars and concrete, comparing the results of the natural biopolymeric additions with the commercially available additives/ admixtures used to induce similar properties in mortar and concrete.
The paper concludes that the observed effects of use of these bio-polymeric additions on the properties of Mortar and Concrete would inspire more researches in these areas which would further add sustainability of the Concrete Constructions. The Paper was presented and Published at the 13th NCB Int Seminar