The development length of a deformed reinforcement bar can be expressed as $$\left( {1/k} \right)\left( {\phi {\sigma _s}/{\tau _{bd}}} \right).$$

From the $$IS:$$ $$456$$-$$2000,$$ the value of $$k$$ can be calculated as _________________.

As per $$IS$$ $$456:2000$$ for $$M20$$ grade concrete and plain barsin tension the design bond stress $${\tau _{bd}} = 1.2\,\,MPa.$$ Further, $$IS$$ $$456:2000$$ permits this design bond stress value to be increased by $$60\% $$ for $$HYSD$$ bars. The stress in the $$HYSD$$ reinforcing steel bars in tension $${\sigma _s} = 360\,MPa.$$ Find the required development length, $${L_d},$$ for $$HYSD$$ bars in terms of the bar diameter, $$\phi $$ ______________.

In the design of a reinforced concrete bean the requirement for bond is not getting satisfied. The economical option to satisfy the requirement for bond is by

As per $$IS:$$ $$456$$-$$2000,$$ consider the following statements:

$$1.$$ The modular ratio considered in the working stress method depends on the type of steel used.
$$2.$$ There is an upper limit on the nominal shear stress in beams (even with shear reinforcement) due to the possibility of crushing of concrete in diagonal compression.
$$3.$$ A rectangular slab whose length is equal to its width may not be a two-way slab for some support conditions.

The TRUE statements are