Question

5. What does the Grade of reinforcing bars represent? 6. How are the compressive strength and tensile strength of concrete determined? Describe the specimen size, shape, and test setup.

help no 6

Answer 1

Answer 6: Compressive Strength = Compressive Strength is the obility of material on Structure to carry the loods on its surface without any chuck an deflection Combuessive Strength = Load Procedure to Cross-sectionul Area determine Compressive Strength :- Specimen Used : Cubical Mould of size 15cm x 15cm x 15cm cu tocmx locm x locm Commonly Cubical Mould (15x15x15 cm) is used Step 1: Concrete is Powned into the mould & tempered Proßenly so as not to have any voids. Step 2: Cube filled with concrete is left in open air for 24hn Step 3: Aften 2 4hrs moulds are removed & the specimen . is but in woken for curing Slep 4: These specimen are tested after 7,14,21,28 doys cop cuning Slep 5: Aften full curing Beriod that is 28 days the specimen tested In Compression testing machine (CTM) gives the Compressive Concrete of the Concrete Helc

Tensile Strength: → Ability to resist clongation is tensile Strength → Tensile Strength = 10 -15% of Compressive Strength → 4 is determined by following 3 tests: - o Unoxial tensile test 3) Split Cylinder test * Flexwe test → Procedure :- (flexure test) Specimen Size : 150mm width, 150mm depth & the length should not be atleast three times the depth. Commonly 150mm x 150mm x 7oomm Used Step 1: Pour consiete into the mould, Aempoxed well, without any voids Step 2: Let A dry for 24 hours & then cure it in water for 14 & 28 days Step 3: Place the specimen in flexural desting machin e and apply load . Looking state, u = sbd² Step 4: Load the specimen until feilure accurs & the leading gives tensile Strength of Connete. PC (CIS