Civil Engineering - Building Materials - Discussion

Anyone can Explain the limits of expansion joints for different structures?

Why all questions are having answer all of the above? we cannot able to understand this type of question.

Expansion joint in 12 m? I have doubt in that.

Expansion joint is provided for > 45m.

"The dry sand and the sand completely flooded with water, have practically the same volume".

How can this happen?

Same thing that concrete structure have expansion joint when the length is increased 45 m.

No, it's 20m for conc. And 45 for rcc.

The bulking of sand should be taken into account when volumetric proportioning of the aggregates is adopted. Otherwise, less quantity of concrete per bag of cement will be produced, which naturally will increase the cost of concrete. Also, there will be less quantity of line aggregate in the concrete mix which may make the concrete difficult to place.

When moisture content is increased by adding more water, the sand particles pack near each other and the amount of bulking of sand is decreased. Thus the dry sand and the sand completely flooded with water have practically the same volume.

The dry sand and the sand completely flooded with water, have practically the same volume, at initial stage of adding water to a measure of dry sand, the sand bulks that is increasing in volume but this increase doesn't continue indefinitely, bulking in sand depends on the % of moisture, up to 5% of moisture makes the sand bulk greatly. At a certain % of moisture content, the bulking cases and the volume of the moistened sand begins to decrease. Experiments have shown that when all the voids in the sand are filled with water about 14% moisture (sand saturated with water) its volume practically becomes equal to the measure of dry sand.