ARMATURA+ announces about the release of advanced performance fiberglass reinforcements!
Fiberglass reinforcements are a relatively new product, and their properties are for the most part higher as compared with their metal analogs, but some parameters such as low elastic modulus and low adhesion of hardened epoxy binder impose certain restriction on their application in heavy loaded structures.
How to solve these two problems and is it possible to increase material elastic modulus as such?
Let’s approach the problem fundamentally,… What is elastic modulus? It’s body’s capability of elastic deformation (i.e. with possibility to return to the original state) under the action of external force. Metal elastic modulus is about 200,000 MPa, fiberglass – 55,000 MPa. It turns out that under the same load metal will extend less, thus deflection of a concrete structure will be less as well. Concrete can only shrink, not stretch, so the more reinforcement length increases, the earlier concrete cracks. That is why fiberglass-reinforced concrete is less crack resistant. Is there any way out? There two solutions:
1. To admix additives increasing concrete time-yield, the so called plasticizing agents (providing the possibility to extend more).
2. To create not just a concrete structure with reinforcements inside, but a fiberglass-concrete composition, where glass fibers are integrated in the concrete structure and linked with concrete at the microlevel. For example, bimetal structures, when strength and crack resistance of one metal increases 3-5 times in bimetal composition. (Watch a good video here http://www.modificator.ru/terms/resistance.html). Concrete can be reinforced immediately with glass fiber, but it is hard to do, besides, glass fiber is not stable enough in the alkali concrete medium. Glass fiber can be poured over with a polymeric binder (and that is exactly what is done by the majority of manufacturers) and then notсhes can be made for linkage, but still it’s not a composition of two metals, because polymer surface is glossy. One can integrate in the polymer surface some material for the grain size to be closer to grain size of concrete mixture (for example, sand). The result will be much better, but cracks in hardened concrete mixture are produced not by sand, but cement crystals, so we need a coating most similar to cement grains in size! Such coating does exist…it’s finely grinded stone minerals of a special composition.
For more than a year we’ve been experimenting together with Ogarev Mordovian State University and Nanotechnology and Nanomaterial Center, and in the beginning of 2014 Mineral+ branded composite reinforcement production will be launched. The cost of products, according to the preliminary estimate, will be approximately the same as the cost of conventional composite reinforcements. The reinforcements have unique properties and have no analogs at the domestic market. It remarkably broadens the range of concrete products, which can be fiberglass reinforced. At present the product is undergoing a number of tests, the results of which will be published at out website ruarmatura.ru upon completion, approximately in November of this year.