## 4 Concluding Remarks  
This paper presented the results of an experimental program conducted to evaluate the influence of five main parameters of ambient cured FS-GPC on fresh and hardened properties. The following key conclusions have been drawn from this study:  
* Increasing the slag replacement levels and decreasing the alkaline activator content resulted in a reduction of workability for all FS-GPC mixes. The slag contents have substantial influence on the slump values at higher molarity of NaOH solution M = 14, lower AAS content (35%), and lower value of SS/SH ration (2.0). The workability of FS-GPC mixes was also decreased by increasing the molarity (10 M to 12 M and 14 M) of NaOH solution. The influence of NaOH solution concentration was more noticeable for the mixes with higher slag content. Increasing the sodium silicate content (SS/SH = 2.0 to 2.5 or 3.0) in AAS also led to a decrease in workability of the mix. The additional water can be used to enhance the workability of FS-GPC mixes in situations where high workable (100 mm to 150 mm) concrete mixes are desired, keeping in view the strength requirements. Figure 19: The compressive strength variations of groups A and D mixes with different SS/SH ratios. Figure 20: The comparison of test and estimated values of elastic modulus of GPC mixes specimens at the age of 28 days. * The increase in the slag contents from 10% to 50% resulted in an increase in the compressive strength for the mixes at a rapid rate till the age of 28 days, after which the rate of development of strength slowed down. The compressive strength of FS-GPC mixes was also increased by increasing the molarity (10 M to 12 M, and 14 M) of NaOH solution and lowering the AAS content to 35%. The influence of amount of alkaline activator seems to be more pronounced at lower levels of slag contents. The influence of alkaline activator was more noticeable at early age of GPC mixes, i.e., 7 to 14 days, with little or no effect at 90 days strength. The mixes showed increase in compressive strength by increasing SS/SH ratio from 2.0 to 2.5, whereas beyond 2.5 it decreased. The strength of FS-GPC mixes decreased with the addition of extra water (excluding that used for preparing AAS). * The practicable mix for FS-GPC, with slump value in the range of 60-100 mm and 28 days compressive strength values in the range of 30-50 MPa, suitable for various concreting applications, i.e., columns, beams, and foundations, can be obtained by limiting the slag content to 20% or 30%, SS/SH ratio to 2.0 or 2.5, molarity of NaOH solution to 10 M or 12 M, and alkaline content to 40%. * The tensile and flexural strength of FS-GPC mixes showed similar trends to that of the compressive strength. The tensile and flexural strength of FS-GPC increased by increasing the slag replacement levels, molarity of NaOH solution, and SS/SH ratio (2.0 to 2.5) and decreasing the alkaline activator content (40% to 35%). The influence of slag content, molarity of NaOH solution, and AAS content on the elastic modulus of FS-GPC mixes was also similar to that of the compressive strength. However, the influence of SS/SH ratio on the static modulus was different than the compressive strength. Increasing the SS/SH ratio from 2.0 to 2.5 had no effect on the elastic modulus, while a decrease was observed when it was increased from 2.5 to 3.0. * The expressions provided by [PERSON] et al. and [PERSON] and [PERSON] have overestimated the values of flexural strength as compared to the present study. The values of tensile strength predicted by [PERSON] et al. were much higher than the experimentally measured values of this study. The values of elastic modulus predicted by [PERSON] et al. were higher, whereas those predicted by [PERSON] and [PERSON] were much lower than the present study. From the test results of the present study, Equations (6), (11), and (17) are proposed to predict the tensile strength, flexural strength, and static modulus of ambient cured FS-GPC mixes, respectively.