Answers

 The application of grillage foundation are:

1. This type of foundation is appropriate to construct for buildings of light construction materials on weak soils.
2. This foundation is needed to save up to 30%.
3. Don’t permit to build the other type of foundation in areas where soil characteristics and conditions of their occurrence weak.
4. The load must be anticipated to be relatively small for construction.

Polymer cement concrete is a composite concrete that consists of synthetic polymer within the binding material. Polymer concrete has advantages of higher properties, low energy requirements, and low labor costs. It is also called Polymer Portland cement concrete (PPCC) or latex-modified concrete (LMC).

Read more on polymer concrete-

Polymer Cement Concrete: Properties and Uses

Mortar mix ratio i.e. proportioning of cement sand in mortar provides consistency in the performance and appearance of masonry construction. Proper proportioning of mortar ingredients helps in having the following advantages:

• Uniformity of strength
• Uniform workability
• Uniform color
• Uniformity of proportions and yields

Mainly the proportioning of the cement and sand for mortar is conducted by volume proportioning compared to weight proportion.

The types of cement mortar are in detail explained in the article below-

Mortar Mix Ratio Proportioning for Masonry Construction

Answer-

1. Without knowing the ultimate strength of the concrete mix, the results obtained on the 7th day can not be declared as right or wrong.
2. Considering the results obtained on the 7th day, i.e, 8.137 N/mm2, the designed strength of the concrete mix shall be M12.
3. The results obtained on the 7th day must be 66% of the ultimate strength. So the ultimate strength of the concrete for the mix that can be expected on 28th day shall be 12 N/mm2.