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The durability of reinforced concrete (RC) pipes depends upon the corrosion resistance of the reinforcing steel and the resistance of concrete mixes against an aggressive environment. This research paper aims to compare the performance of R.C. pipes made of ordinary Portland cement (OPC) concrete mixtures with others made of two different geopolymer concrete mixes based on different ratios of granulated blast furnace slag (GBFS), fly ash (FA), and pulverized red brick (RB) subjected to three different environments, ambient, tap water (TW), and an aggressive environment, and a solution of 10% magnesium sulfates + 5% chloride (MS-CL). An accelerated corrosion setup has been applied to accelerate the corrosion process in the tested samples. The evaluation of change of compressive strength of concrete and microstructure of different mixes was investigated too. Fourier transform infrared (FTIR) spectroscopy has been studied on all pipes. Geopolymer concrete mixes based on 90% GBFS and 10% RB show better results in all cases. Geopolymer concrete mixes based on 63% GBFS, 27% FA, and 10% RB increase the concrete compressive strength in the magnesium sulfate and chloride environment by 5% compared to tap water. It can be concluded that the geopolymer concrete mixes produced of 90% GBFS and 10% RB perform well under all environments, and its microstructure shows stable behavior in an aggressive environment.

Fire in buildings is nearly always man-made, i.e. resulting from negligence or error, which can cause immense damage in terms of lives and property [1]. But when we deal with nuclear constructions (like nuclear power plants NPP), the dangers of fire do not stop only at the potential damage that the concrete structure is exposed to, but rather extends to the risk of a radiation leak that may cause serious damage to the human life and all living creatures. For this reason, designers of nuclear constructions (which are mostly reinforced concrete) give special attention for making the concrete structure capable of resisting the effects of fire or thermal leakage, as well as having a high ability to resist all types of radiation (specially gamma ray radiation). On the other hand, incorporation of nano additives into concrete structures components become a promising field of research these days. The current study tries to investigate the effect of using different nano materials (Nano silica, Nanoclay, and hybrid mix of both materials) as a cement replacement into the concrete radiation resistance ability (in the term of linear attenuation coefficient µ). Results showed remarkable enhancement on the values of µ at all temperature degrees. For the conduct of reliable estimate and prediction of the values µ, this study adopts the fuzzy logic models as powerful tools of artificial intelligence to model the non-linear cause and effect relationships. Prediction results was superior when compared with traditional linear regression analysis.