To separate the terms “modified bitumen” and “modified concrete”, one needs to understand what these materials are, their use and methods to adjust their properties.
Scientists refer to modified concrete as the concrete of the millenium. Additives can control the process of material formation and create highly functional construction materials. Modified concrete has higher density, better cold-endurance and water resistance.
Application of additives helps to improve durability of concrete structures built of monolithic or composite concrete. The amount of modifiers used is usually less than one tenth or even one hundredth of percent of cement mass.
Depending on their functionality, additives are divided into four groups:
- additives designed for alteration of mineral binders without chemical interactions;
- additives interacting with binders, resulting in hardly soluble and poorly dissociated complex compounds;
- additives which become crystallization nodes;
- organic surfactants.
The scope of application of modified concrete is little or no different from the application of usual concrete: repairs of asphalt concrete roads, reconstruction of hydroengineering structures, bridge construction, underground development, etc.
Modified bitumens in turn found industrial application in road construction, as well as roofing and waterproofing.
Bitumens are most often modified by introduction of polymers, allowing to achieve better performance, such as:
- improved performance at high and low temperatures;
- improvement of elasticity;
- increased fatigue resistance;
- improvement of cohesion and adhesion with fillers;
- increased aging resistance.
The practical difference between modified bitumen and concrete is in the type of the basic material influenced by additives. In the former it is bitumen, in the latter case it is cement.