31096

بررسي تاثير سنگ آهك و ميكروسيليس بر خواص مكانيكي و فيزيكي سيمان پرتلند

دكتري تخصصي (PhD)

مهندسي مواد و متالورژي- سراميك

1399

1403/5/13

مهدى داراب - رحيم نقي زاده

/

مهندسي مواد و متالورژي

/

1403/05/22

Investigating the effect of limestone and microsilica on the mechanical and physical properties of Portland cement

1/1/1900 12:00:00 AM

Portland cement is one of the most widely used materials by mankind. But its production has faced challenges due to CO2 emission and greenhouse gas generation. One of the ways to reduce the above problem is to prepare adhesives or mixed cements containing Portland Vic cement or some additive components such as metakaolin, micro silica, fly ash, slag, natural pozzolans, some of which are being mass produced and Others are in the research and development stage. Cement has cement properties, that is, due to the reaction of its different phases, especially organic (C3S) and billet (C2S) with water, they give hydrated phases such as C-S-H, Ca(OH)2. Most additives have pozzolanic properties. Gives hydrated phases such as C-S-H or C-A-S-H. The price of micro silica is much higher than cement. For this purpose, it has become popular to investigate the three-component systems of Portland cement-microsilica-limestone in order to control the price of mixed cements. In this research, it is focused on this system. Microsilica has a pozzolanic property and limestone has different roles such as filler, the place of germination of hydrated phases, compressing the transition zone, creating new hydrated phases by reacting with C3A and forming the hydrated phase of hydrated calcium aluminate monocarbonate (). In this research, three The category of mixed cement containing microsilica additive up to 6%, containing limestone up to 30% by weight and three-component mixed cements containing limestone and microsilica were investigated together. The results showed that the 28-day compressive strength of mixed cements containing 6% replacement of microsilica is about 10 %, the replacement of 10% limestone by 8.6% and mixed cement containing 15% limestone and 2% microsilica increased the strength by 1.7% compared to only Portland cement samples. X-ray diffraction patterns showed that in the case of cements The mixture containing 6% microsilica Ca(OH)2 was completely destroyed and this was the indicator of its pozzolanic reaction. And in the case of mixed cements containing limestone, some hydrated calcium aluminate monocarbonate phase is formed, and a large amount of CaCO3 has only played the role of filler and germination. Infrared spectra (FTIR) of different samples indicate the presence of vibrations related to different ettringite phases. Monosulfate, portlandite, C-S-H, monocarbonate and limestone were observed in the respective samples.

ميكروسيليس , سنگ آهك

Microsilica , Limestone

Majid Kano

Dr. Mehdi Darab - Dr. Rahim Naghizade