$(2-$pt$)$ Describe concrete compressive strength by means of type of specimen and curing period. planing $$ Casting $f$ Cement $+$ water $$ cement past $$ cover all type depend of sific and aggr

$(1-$pt$)$ Why is it important that a reinforced concrete beam be tension$-$controlled?

cheals

$(1-$pt$)$ Briefly explain one advantage of ultimate strength design as compared to traditional factor of safety methods$($working stress methods$).$

$(1-$pt$)$ Describe the maximum tensile bending stress in a plain concrete test at failure?

High strength concret$-$o $100$Mpa

$(1-pt$ Does Whitney equivalent rectangular stress represent actual stress distribution?

$(2-$pt$)$ A beam height is $60cm,$ the location of neutral axis is found to be $20cm$ from upper compressi fiber, what type of failure do you expect to occur and why?

$(1$ pt$)$ In ultimate strength design, why do live loads have a higher factor $(1\mathrm{.}6)$ than dead loads $(1\mathrm{.}2)?$ the dead load

$(2-$pt$)$ Find balanced steel ratio of rectangular beam $)=30cm,d=(50cm{f}_y=280$MPa,${}_1=0\mathrm{.}85$ and $E_5=200000$MPa.

$P_b$

$n{A}_s$

$9.(3-$pt$)$ What is the equivalent concrete area for uncracked beam $)=200,h=(150$ that contains $2$$$29$ st area and $E_C=25000$MPa, and $E_S=200000$MPa

$n=\frac{Es}{Ec}=8$

$Ac=7**1\mathrm{.}290=9\mathrm{.}03=903m{m}^2$

$A_s=1\mathrm{.}290$

$(3-$pt$)$ What is the maximum moment capacity $(M_{c.})$ of rectangular plain concrete beam $h=300mmb=200mm$ with $fc=25$MPa

$$

N$.$A

$11.(4-$pt$)$ Find location of neutral axis of rectangular beam $)=250,d=(500$ with tensile steel $419,$ and modular ratio $=8,$ then calculate maximum external bending moment $.($assuming cracked section with elastic stress$).$