In slump test, each layer of concrete is compacted by a steel rodcm long and ofmm diameter for

If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respetively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation

To prevent segregation, the maximum height for placing concrete, is

The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than

A construction joint is provided where

An aggregate is known as cyclopean aggregate if its size is more than

Strength of concrete with passage of time

For given workability the grading requiring the least amount of water is one that gives

Le-Chatelier's apparatus is used for testing

Curing of pavements, floors, roofs and slabs, is done by

Sand generally contains salt if it is obtained from:

Pick up the correct statement from the following:

Placing of concrete should preferably be done at a temperature of

Setting time of cement increases by adding

For concreting tunnel linings, tran-portation of concrete is done by

The entrained air in concrete

Workability improved by adding

If the average compressive strength iskg/cm² and standard deviation isthe co-efficient of variation is

For the construction of thin R.C.C. structures, the type of cement to be avoided, is

If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:the grade of concrete, is

Pick up the incorrect statement from the following. While performing preliminary test on concrete

The main object of compaction of concrete, is:

The minimum percentage of chemical ingredient of cement is that of

'Ware house pack' of cement means

Pick up the incorrect statement from the following:

The impurity of mixing water which affects the setting time and strength of concrete, is

Horizontal construction joints in concrete walls are generally provided at

The aggregate impact value of the aggregate used in

The operation of removing humps and hollows of uniform concrete surface, is known as

If the slump of a concrete mix ismm, its workability is