Physical, chemical and mechanical properties of high belite cement (HBC) blended with high pulverized fly ash (HPFA) with stable ratio of silica fume (SF) in comparison with Portland cement (OPC) were investigated. Results showed that the water of consistency and setting times (Initial and final) tended to increase with the increase of HPFA content. The bulk density and compressive strength were also improved and enhanced with the increase of HPFS content at all hydration times, but only up to 15 % HPFA, and then decreased with further increase.  However, the total porosity slightly decreased, but started to increase with further increase of >15 % HPFA. The free lime content of the pure OPC and HBC gradually were increased as the hydration times progressed up to 90 days, while those of blended cements increased only up to 7 days and then decreased onward. The results were confirmed by measuring the heat of hydration and ultrasonic pulse velocity for the optimum cement pastes comparing with those of both OPC and HBC. The heat of hydration of the optimum cement pastes was decreased at all hydration times and become lower than those of OPC and HBC. The ultrasonic pulse velocity test (USPV) proved that the uniformity and quality of the matrix of the hardened cement pastes are good with no cracks.

The activated pulverized rice husk ash (PRHA) as a pozzolanic material mixed with Portland cement (OPC) in various ratios was synthesized as geopolymer cement. The alkaline activator was prepared from a mixture of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Effect of OPC replacement on the various properties of the synthesized geopolymers was evaluated. The results showed that the water of consistency sharply decreased with the increase of the OPC addition, while the setting times (initial and final) slightly decreased. The water absorption and apparent porosity reduced with OPC replacement at the expense of PRHA merely up to 18 wt. % content, and then increased. The bulk density as well as flexural and compressive strengths improved and enhanced also up to 18 wt. % OPC content, but then declined with any further increase. The free lime content increased up to 3 days of curing and then decreased onward due to its consumption during the pozzolanic reactions. The 18 wt. % OPC geopolymer mix is the optimum mix, where it achieved the better water absorption (6.89 %), bulk density (1.9099 g/cm3), apparent porosity (15.62 %), flexural strength (5.54 MPa) and compressive strength (58.25 MPa) at 90 days curing times. The ultrasonic pulse velocity test largely confirmed the obtained physical and mechanical characteristics. The FTIR spectra showed that the spectra of G18 geopolymer was more pronounced due to the formation of NASH geopolymer-gel needed to ensure better conformity between different constituents in the whole system that responsible for the improvements in the mechanical properties. The microstructure of the optimum G18 geopolymer mix is well-defined with no or little pores that responsible for the improving of physical properties and the enhancement of mechanical strengths, whereas the microstructure of G24 is more porous and heterogeneous matrix which was contributed to the reduction of mechanical strengths.

The influence of the prepared carboxy-methylated lignin extracted from sugarcane bagasse was investigated. Results showed that the w/c ratio and also setting times of the blank (L0) were reduced with the lignin content. The heat of hydration, combined water content, bulk density and compressive strength of the blank (L0) slightly increased with increasing of lignin content, but only up to 0.3 % lignin (L5) and then decreased. The free lime content decreased with the lignin content nearly at all hydration times up to 90 days due to the gradual reduction of the cement portion. The total porosity of the blank (L0) reduced gradually with lignin content up to 0.3 % lignin, and then increased with further increase of lignin. The FTIR spectra illustrated that the rate of hydration increased with lignin content. The SEM-EDAX image analysis showed the improved microstructure of cement pastes in presence of carboxy-methylated lignin when compared with that of the blank.

The durability (chemical resistence) of the Portland cement (OPC), belite cement (BC) and the optimum belite cement (B4), which their physical and chemo/mechanical properties were perviously investigated in Part I, against 4 % MgSO4 and 4% MgCl2 solutions up to 12 months in terms of compressive strength, total sulfate and total chloride was evaluated and studied. Results showed that the optimum belite cement (B4) containing 15 % High pulverized fly ash (HPFA) and 5 % Silica fume (SF) could be resisted up to 6 months, while that of BC could be withstood only up to 5 months, and the OPC could not resist more than three months of immersion in 4% MgSO4 solution. The compressive strength values exhibited by the samples immesed in sulfate solution at 3, 5 and 6 months of immersion were 83.81, 76.38 and 91.13 MPa, respectively. The same trend was displayed when the same samples were exposed to 4% MgCl2 solution. The compressive strength values exhibited by the same samples exposed to chloride solution at 3, 5 and 6 months of immersion were 84.49, 82.23 and 93.32 MPa, respectively. The total sulfate and chloride contents were enhanced with immesion time up to 12 months, but their values were the minimum with B4 and the maximum with OPC, while with BC were the medium. The optimum cement batch (B4) achieved the highest resistance where it recorded the lowest values for sulfate and chloride ions, but the OPC exhibited the lowest resistance where it recorded the highest values of sulfate and chloride contents at all immersion ages till 12 months.