Project summary
Concrete is a material with a very high compressive strength but extremely low flexural strength. That is why, in practice, this inconvenience was overcome by embedding steel. Unfortunately, the production of steel necessary for the ever growing construction industry is a high polluter, as well as the cement production. Consequently, developing of new cement based materials with increased flexural strength is essential for the construction industry. The solution for obtaining such concretes seems to be in the field of nanotechnology. Our previous investigations have shown that by using a combination of quartz powder and organosilane it is possible to increase both the flexural and compressive strength of a concrete material. These effects are due to the hydrophilic nature of organosilane and the reactivity of silane molecular ends with the -OH groups present both on the surface of silica and the cement matrix. In the present project we plan to continue the previous investigations in a systematic manner using silica fume instead of quartz powder and to develop a concrete material with even higher flexural strength and lower permeability. The main advantage of using silica fume instead of quartz powder is that silica fume has pozzolanic reactivity, smaller particle sizes and is a byproduct of the industry which will increase the ecological importance of the produced material. The investigations will make use for the first time of the advantages of low field nuclear magnetic resonance (NMR) diffusometry and relaxometry techniques. The outcomes of the NMR investigations will be compared with strength test measurements in order to find the optimal composition of the concrete product.
Concrete is a material with a very high compressive strength but extremely low flexural strength. That is why, in practice, this inconvenience was overcome by embedding steel. Unfortunately, the production of steel necessary for the ever growing construction industry is a high polluter, as well as the cement production. Consequently, developing of new cement based materials with increased flexural strength is essential for the construction industry. The solution for obtaining such concretes seems to be in the field of nanotechnology. Our previous investigations have shown that by using a combination of quartz powder and organosilane it is possible to increase both the flexural and compressive strength of a concrete material. These effects are due to the hydrophilic nature of organosilane and the reactivity of silane molecular ends with the -OH groups present both on the surface of silica and the cement matrix. In the present project we plan to continue the previous investigations in a systematic manner using silica fume instead of quartz powder and to develop a concrete material with even higher flexural strength and lower permeability. The main advantage of using silica fume instead of quartz powder is that silica fume has pozzolanic reactivity, smaller particle sizes and is a byproduct of the industry which will increase the ecological importance of the produced material. The investigations will make use for the first time of the advantages of low field nuclear magnetic resonance (NMR) diffusometry and relaxometry techniques. The outcomes of the NMR investigations will be compared with strength test measurements in order to find the optimal composition of the concrete product.