The raw materials used in Portland Cement production are:

what are the different types of resin cements in dentistry and their indications

Organic impurities into the aggregate increase the strength and durability of concrete. Select one: O True O False

Explain why shape, surface texture, and gradation are more important for aggregate use in normal strength concrete than strength and origin of rock formation.

please quickly thanks !

Design a concrete mix according to the following conditions:   Design Specifications  Concrete ramp (not reinforced) Slab thickness =270 mm Design strength (fc) = 25.5 MPa Standard deviation s= 1.86 MPa on 200 specimens Environment = Severe exposure to freeze-thaw and de-icing chemicals Slump = 50 mm   Materials Available Cement: Type GU; specific gravity 3.15 Admixture: Air entraining admixture  8 ml/1% air/100 kg cement . Coarse Aggregate: Nominal maximum size = 37.5 mm Type = Crushed stone Bulk oven-dry specific gravity = 2.63 Absorption = 2.1% Oven-dry rodded density = 1755 kg/m3 Moisture content = 1.5% Fine Aggregate Type = Natural sand Bulk oven-dry specific gravity = 2.55 Absorption = 3.1% Moisture content = 4.3% Fineness modulus = 2.40

Design a concrete mix for the following performances and ingredients:• Compressive strength at 28 days = 35MPa, slump 85 mm• Crushed coarse aggregate of size 14 mm readily available• Fine aggregate is washed coarse  sand, fineness modulus = 2.5• Specific gravity of combined aggregate =2.6• Water absorption of fine aggregate = 5%• Water absorption of coarse aggregate = 3%• Air-dry moisture content of coarse aggregate = 6%• Air-dry moisture content of fine aggregate = 2%

The quality of aggregate packing affects: a) Cement use b) Slump c) Corrosion d) Early cracking

Which of the following material is/are used as an accelerator’s additive for cement? a. Sodium Chloride b. Caustic Soda c. Calcium Chloride d. Nitrogen e. Barite f. Bentonite g. Gypsum

Design the concrete mix according to the following conditions:  Design environment Tennis court, subjected to freezing Required design strength =21 MPa Slab thickness=300 mm Statistical data indicate a standard deviation of compressive strength of 3.7 MPa is expected (for 50 samples) Only air entrainer is allowed Available materials: Air=7% Air entertainer: Manufacturer specification is 9.0 ML /1% air/100kg cement Slump=50 mm Coarse aggregate: 50 mm nominal maximum size, crushed stone Bulk volume oven-dry specific gravity=2.61, absorption=2.8%, oven-dry rodded density=1870 kg/m3 Moisture content=1% Fine aggregate: Natural sand Bulk oven-dry specific gravity=2.54, absorption=3.4% Moisture content= 4.5% Fineness modulus=2.60 Cement: Type I, relative density=3.1