Recent questions in Concrete Structures

In the context of provisions relating to durability of concrete, consider the following assertions:$\textbf{Assertions:(1)}: $ As per $IS \: 456-2000$, air entrainment to...

As per $\text{IS } 456-2000$ for the design of reinforced concrete beam, the maximum allowable shear stress $(\tau_{\tau \text{max}})$ depends on thegrade of concrete and...

A haunched (varying depth) reinforced concrete beam is simply supported at both ends, as shown in the figure. The beam is subjected to a uniformly distributed factored lo...

A $450 \: mm$ long plain concrete prism is subjected to the concentrated vertical loads as shown in the figure. Cross section of the prism is given as $150 \: mm \times 1...

In shear design of an RC beam, other than the allowable shear strength of concrete $( \tau _c)$, there is also an additional check suggested in IS $456-2000$ with respect...

A reinforced concrete (RC) beam with width of $250$ mm and effective depth of $400$ mm is reinforced with $Fe415$ steel. As per the provisions of $IS \: 456-2000$, the mi...

For $M25$ concrete with creep coefficient of $1.5$, the long-term static modulus of elasticity (expressed in MPa) as per the provisions of $IS:456-2000$ is _____

A propped cantilever of span $L$ carries a vertical concentrated load at the mid-span. If the plastic moment capacity of the section is $M_p$, the magnitude of the collap...

A concrete gravity dam section is shown in the figure. Assuming unit weight of water as $10 \: kN/m^3$ and unit weight of concrete as $24 \: kN/m^3$, the uplift force per...

According to $IS \: 456 – 2000$, which one of the following statements about the depth of neutral axis $x_{\text{u, bal}}$ for a balanced reinforced concrete section is c...

A pre-tensioned rectangular concrete beam $150$ mm wide and $300$ mm depth is prestressed with three straight tendons, each having a cross-sectional are of $50 \: mm^2$, ...

A column of size $450 \: mm \times 600\: mm $ has unsupported length of $3.0$ m and is braced against side sway in both directions. According to $IS \: 456:2000$, the min...

A simply supported reinforced concrete beam of length $10$ m sags while undergoing shrinkage. Assuming a uniform curvature of $0.004 m^{-1}$ along the span, the maximum d...

In a pre-stressed concrete beam section shown in the figure, the net loss is $10 \%$ and the final pre-stressing force applied at $X$ is $750$ kN. The initial fiber stres...

Consider the following statements for air-entrained concrete:Air-entrainment reduces the water demand for a given level of workabilityUse of air-entrained concrete is re...

The two columns below show some parameters and their possible values.$\begin{array}{ll} \textbf{Parameter} & \textbf{Value} \\ P – \text{ Gross Command Area} & I – 100 \t...

Two beams are connected by a linear spring as shown in the following figure. For a load $P$ as shown in the figure, the percentage of the applied load $P$ carried by the ...

The static indeterminacy of the two-span continuous beam with an internal hinge, shown below, is _______

The modulus of elasticity, $E=5000 \sqrt{f_{ck}}$ where $f_{ck}$ is the characteristic compressive strength of concrete, specified in $IS:456-2000$ is based ontangent mod...

In a reinforced concrete section, the stress at the extreme fibre in compression is $5.80$ MPa. The depth of neutral axis in the section is $58$ mm and the grade of concr...

Match the information given in Group – I with those in Group – II.$\begin{array}{llll} {} & \text{Group – I} & {} & \text{Group – II} \\ P & \text{Factor to decrease ulti...

A rectangular concrete beam $250$ mm wide and $600$ mm deep is pre-stressed by means of $16$ high tensile wires, each of $7$ mm diameter, located at $200$ mm from the bot...

The cross-section at mid-span of a beam at the edge of a slab is shown in the sketch. A portion of the slab is considered as the effective flange width for the beam. The ...

A concrete beam prestressed with a parabolic tendon is shown in the sketch. The eccentricity of the tendon is measured from the centroid of the cross-section. The applied...

The sketch shows a column with a pin at the base and rollers at the top. It is subjected to an axial force $P$ and a moment $M$ at mid-height. The reaction(s) at R is/are...

Which one of the following is categorised as a long-term loss of prestress in a prestressed concrete member?Loss due to elastic shorteningLoss due to frictionLoss due to ...

A $6$ m long simply-supported beam is prestressed as shown in the figure.The beam carries a uniformly distributed load of $6$ kN/m over its entire span. If the effective ...

A singly-reinforced rectangular concrete beam of width $30$ mm and effective depth $400$ mm is to be designed using $M25$ grade concrete and $Fe500$ grade reinforcing ste...

A reinforced-concrete slab with effective depth of $80$ mm is simply supported at two opposite ends on $230$ mm thick masonry walls. The centre-to-centre distance between...

An RCC beam of rectangular cross section has factored shear of $200$ kN at its critical section. Its width $b$ is $250$ mm and effective depth $d$ is $350$ mm. Assume des...

The frequency distribution of the compressive strength of $20$ concrete cube specimen is given in the table.$$\begin{array}{|c|c|} \hline f \text{ (MPa)} & \text{Number o...

Two rectangular under-reinforced concrete beam sections X and Y are similar in all aspects except that the longitudinal compression reinforcement in section Y is $10 \%$ ...