Question

6) WHAT ARE THE DIFFERENCES BETWEEN CHEMICAL and MINERAL ADMIXTURES?

Answer 1

CHEMICAL ADMIXTURE	MINERAL ADMIXTURE
Chemical admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes.	while mineral admixtures are Inorganic materials that have pozzolanic or latent hydraulic properties, these very fine-grained materials are added to the concrete mix to improve the properties of concrete.
chemical admixtures improve the quality of concrete during mixing, transporting, placing and curing.	mineral admixtures affects the nature of the hardened concrete through hydraullic or pozollanic activity.
Chemical admixtures improve the workability of the concrete.	mineral admixtures improves the strength governing properties of concrete.
chemical admixtures indirectly affects the strrength of cincrete	mineral admixtures directly affects the strength of the concrete.

chemical admixtures are mixed in concrete at the timing of mixing.

mineral admixters are mixed in cement generally while manufactering.

chemical admixtures are very intensive in nature and are required in very less quantity. Dosage ranges from 0.2% to 2% by weight of cement.	mineral admixtures are not so much intensive and the quantity required is comparatively high.
chemical admixtures also improves air entraining property, retarding and accelerating property of concrete, corrossion inhibitors, shrinkage controlling property of concrete	mineral admixture makes mixtures more economical (enables reduction in total cement content), reduce permeability , increase strength and influence other concrete properties.
simple test on grouts such as marsh cone test or mini slump test can be a fair idea of compatibility between chemical admixtures and cementatious material.	there is no any specific test but by mixing admixtures in different ratios and testing the cement and concrete can lead to the proper quantity of admixture.
eg. air entraining agents , plasticizers, superplasticizers, acceerating agents and retarding agents.	eg. blast furnace slag, fly ash , silica fumes , rice husk, ash, GGBFS