Question

Answer required for following question please:

a. Establish the effect of each of the replacement materials on the strength of concrete in relation to the control sample. Relate the findings to existing literature.

b. Determine the behavior of UPV for each of the cement replacement materials and control. Compare the behavior of UPV with that of strength for each of the concretes and establish any possible trends.

c. Highlight the differences in rebound number between the different concrete samples and compare the surface hardness to strength for each of the concrete types.

d. Provide the indication of the effects of pfa, ggbs, and microsilica on the permeability, and therefore the durability, of concrete in comparison to that of control (0% replacement). This should be associated with the findings from the compressive strength and the other non-destructive tests.

100% PC Concrete (Control)	pfa (30%) Concrete	ggbs (60%) Concrete	Microsilica (csf-10%) Concrete
4644	4967	4902	4.870
4762	4658	4872	4.702
4732	4360	4644	4.532
4918	4854	5000	4.573
4011	4950	4950	4.461
4732	4792	4886	4.505

Schmidt Hammer measurement (Keep Schmidt Hammer Horizontally)

100% PC Concrete (Control)	pfa (30%) Concrete	ggbs (60%) Concrete	Microsilica (csf-10%) Concrete
37.5	29.8	30.9	32.2

Compressive strength measurement (MPa)

100% PC Concrete (Control)	pfa (30%) Concrete	ggbs (60%) Concrete	Microsilica (csf-10%) Concrete
495.6 (KN)	216.8 (KN)	429.3 (KN)	361.5 (KN)
22.03 (MPa)	9.61 (MPa)	19.07 (MPa)	16.04 (MPa)
8344 g	8289 g	8280 g	8143 g

Testing Sheet

	Control	pfa (30%)	ggbs (60%)	Microsilica (10%)
KT- x10-16 m2 Permeability coefficient.	0.023 (m2)	0.011 (m2)	0.026 (m2)	0.031 (m2)
L mm Depth of air penetration	10.6 (mm)	………	11.2 (mm)	12.2 (mm)
Quality class of concrete surface (Table 1)	2	2	2	2

Table 1: Quality classes of cover concrete

Quality of cover concrete	Index	KT (10-16m2)
Very bad	5	> 10
Bad	4	1.0 – 10
Normal	3	0.1 – 1.0
Good	2	0.01 – 0.1
Very good	1	< 0.01

Answer 1