Advanced Concrete Technology

a. Enumerate the importance of Bogue's compounds in ordinary port land cement.

b. Explain briefly Theology of concrete. What are the factors affecting the rheology of concrete?

c. What are the factors affecting strength and elasticity of concrete?

a. Explain the mechanism of 'deflocculation' of cement particles by super plasticizers with neat sketches

b. What is optimum dosage of super plasticizer? How do you determine the optimum dosage of super plasticizer? 

c. What are mineral admixtures? Explain briefly, i) Silica flume ii) G.G.B.S. iii) Fly ash. 

a. Explain the factors affecting the mix design of concretes.

b. Design a concrete mix of Mas grade for the following data:Max size of aggregate - 20 mm; Crushed angular Min/max cement content - 300/450 kg/m'; Max W/C -0.5; Exposure condition - Moderate; Work ability - 100 mm slump: Method of placing - pumping: Quality control-good; Type of chemical admixture - Super plasticizer (Specific gravity - 1.14). Assume 25% replacement of cement by fly ash. Test data for materials:

i) Cement - OPC 43 grade IS 8112.

ii) Specific gravity of cement - 3.15 t

ii) Fly ash-20% Cementations material

iv) Specific gravity of fly ash-2.20

v) Specific gravity of coarse aggregate - 2.60

vi) Specific gravity of fine aggregate - 2.65 [belongs to zone II]

Assume any other data suitably.