Durability study on concrete with Natural viscosity enhancers

Abstract

Concrete is a widely used construction material in the construction industry. Many technological innovations and use of admixtures have improved the quality, usability and durability of concrete. One of the recent improvements is the development of Viscosity Modifying Admixtures (VMA) also referred to as Stabilizers, Viscosity Enhancing Admixtures (VEA) and Water Retaining Admixtures. Today s concrete has to fulfil a extensive variety of requirements in all the fresh and hardened state. In most cases the properties of fresh concrete influence the quality of the hardened concrete and eventually its durability. This means that concrete has to be appropriately proportioned and must remain homogeneous during placing and after compacting in order to avoid the effects such as bleeding, segregation, honey combing, settlement and plastic cracking over the top bar. All these effects would lead to good quality and durability of hardened concrete. newlineSpecial concrete allows faster construction, slender structures, greater durability, much higher final strength and faster strength development. Nowadays Concrete has to be pumped all vertically and horizontally over a long expanse even with high flow and compacting properties. The more advanced the concrete becomes the more sensitive it gets to material variations and fluctuations during production and placing. Production sites are often faced with problems caused by variations in the moisture content or grading of the aggregates and with fluctuations in the fine content of the sand. Construction sites may face difficulties resulting from the location, access or from breakdowns or other stoppages during placing newline