The compressive strength $($MPa$)$ was

determined for matured concrete using

cubes $(100m{m}^3)$ that were $($air$-$dried,

attained SSD$,$ and oven$-$dried$)$ before

rrushed at different rates of loading $($RL$)$:

esults are tabulated, as shown. The most

rasonable values for $x,Y,W$ and $Z$ are

$($C$)x=27$;$Y=29$;$W=28.$

$x=27$;$Y=29$;$W=26$;$Z=26$

$($B$)x=26$;$Y=26$;$W=26$;$Z=26$

$($F$)x=27$;$Y=29$;$W=24$