ملخص البحث :

Cement production uses large quantities of natural resources and contributes to the release of CO2. In order to treat the environmental effects related to cement manufacturing, there is a need to improve alternative binders to make concrete. Accordingly, extensive study is ongoing into the utilization of cement replacements, using many waste materials and industrial. This paper introduces the results of experimental investigations upon the mortar study with the partial cement replacement. Fly ash, silica fume and glass powder were used as a partial replacement, and cement was replaced by 0%, 1%, 1.5%, 3% and 5% of each replacement by the weight. Compressive strength test was conducted upon specimens at the age of 7 and 28 days. Microstructural characteristic of the modified mortar was done through the scanning electron microscope (SEM) vision, and X-ray diffraction (XRD) analysis was carried out for mixes with different replacements. The tests results were compared with the control mix. The results manifested that all replacements present the development of strength; this improvement was less in the early ages and raised at the higher ages in comparison with the control specimens. Microstructural analysis showed the formation of hydration compounds in mortar paste for each replacement. This study concluded that the strength significantly improved by adding 5% of silica fume compared with fly ash and glass powder.

ملخص البحث :

To study the effects of nanomaterials on the microscopic structure of the mortarinterconnection zone that is prepared by a compound bond comprising nanomaterials. And to clarifyits impact on compressive strength improvement. In this study, the compressive strength, SEManalysis and XRD analysis were estimated for mortar containing different amounts of ZrO2, SiO2,Al2O3 and CaCO3 nanoparticles. Four different contents of each nanoparticles' types were used as apartial replacement of cement with 1%, 1.5%, 3% and 5% by the weight of cement. Resultsmanifested that the mortar compressive strength enhancement can be ascribed to the microstructureamelioration of the interfacial transition region. Besides, XRD analysis and SEM micrographselucidated the formation of hydration compounds and the improvement in bonding due to theexistence of nanoparticles.

ملخص البحث :

In the present study, the compressive strength assessments of cement mortar containing different amounts of ZrO2, SiO2, Al2O3 and CaCO3 nanoparticles have been investigated. Four different contents for each nanoparticles type were utilized as a partial replacement of cement 1%, 1.5%, 3% and 5% by the cement weight. The compressive strength was estimated for two ages (7) and (28) days. The end results manifested that the specimens’ compressive strength enhanced via the addition of the nanoparticles of ZrO2 and SiO2 to the paste of cement till 3.0% and then decreased but remained greater than the reference mix. While, the compressive strength of specimens enhanced via the addition of the nanoparticles of Al2O3 and CaCO3 ZrO2 up to 5%. Maximum compressive strength recorded was 42.5 MPa for mixes with 3% nano SiO2 followed by 38 MPa, 37 MPa and 33.5 MPa for mixes with 4% nano Al2O3, 3% nano and ZrO2 and 4% nano CaCO3, respectively.REFERENCES

ملخص البحث :

Silica is considered one of the most prevalent components in the Earth’s shell and is synthesized for use in technological applications. Nevertheless, new methods for finding a better, cheaper, and more ecologically friendly supply of silica with less energy consumption are unavoidable. This study investigates whether nanopowders made from waste with a great silica amount (fly ash and glass) can be utilized as fillers in an epoxy glue to enhance its characteristics. Four different contents (5, 10, 15, and 20 wt%) of nano–fly ash, nanoglass, and nanosilica powder were introduced into the samples. Fourier transform infrared analysis, differential scanning calorimetry analysis, viscosity testing, and microhardness testing were conducted for nanoglass/epoxy and nano–fly ash/epoxy samples, which were compared with the silica/epoxy samples. Results indicated that the nanoglass and nano–fly ash powder have the same impact as nanosilica on the characteristics of epoxy. The hardness and viscosity of epoxy increased with the increase in the added filler. At 20 wt%, the hardness value of the nanoglass/epoxy composites was greater than that of the nanosilica/epoxy and fly ash/epoxy composites by about 15% and 7%, respectively. The results also indicated that the highest viscosity values were obtained when using nano–fly ash powder of 20 wt%. Furthermore, the modification of the epoxy by the nanoparticles had no significant effect on the values of the glass transition temperatures.

ملخص البحث :

. In this study, polymer composites were manufactured with epoxy-based resin and wastes as a mineral additive. The wastes including a high content of silica (Silica fume, glass and fly ash) powder were used as fillers for an epoxy adhesive to improve its wear resistance properties. They were supplemented to mixes in various ratios via substituting the resin from 0 to 20% by weight. Tests of wear rate and hardness were conducted upon all-polymer composites at all fillers ratios. Results indicated that the epoxy hardness increased with increasing the filler addition. Consequently, the addition of wastes that include silica raised the wear resistance of polymer composites; nevertheless, it caused the composites harder materials. The wear rate decreased with increasing the silica fume, glass, and fly ash addition. In the case of fly ash addition, the minimum wear rate was at 15%, and after this percentage, the wear rate increased. However, in the case of glass addition, the minimum wear rate was at 10%, and after this percentage, the wear rate increased.