Question $4$

Explain$/$respond to the following:

a$)$ Alkali$-$aggregate reactions are harmful for aggregates

b$)$ Quality aggregate should be free from fines

c$)$ The preferred shape and texture of aggregates to be used in a concrete mix

d$)$ Gap$-$graded and poorly graded aggregates are not used in concrete mixes.

Question $5$

The table below represents the properties of two aggregates available on site.

a$)$ Find the fineness modulus of the fine aggregate

b$)$ Find the MNA of the coarse aggregate

c$)$ Combine aggregates A and $B$ with a $1$:$2$ ratio and draw the gradation curve of the combined aggregates.

$\backslash$table$[[$Sieve Size,A $(\%$ Passing$),$B $(\%$ Passing$)],[38mm,92,100],[19mm,76,100],[9\mathrm{.}5mm,43,100],[4\mathrm{.}75mm,6,93],[2\mathrm{.}8mm,0,89],[1\mathrm{.}4mm,0,67],[0\mathrm{.}707mm,0,53],[0\mathrm{.}350mm,0,32],[0\mathrm{.}177mm,0,5]]$