Question

The following requirements are specified for concrete construction of a reinforced concrete jetty exposed to sea water and moderate freeze and thaw environment Required Design Strength, fc Slump required Standard deviation Cement 35 MPa 25-75 mnm 4.8 MPa Ordinary portland cement with relative density 3.15 Fine Aggregate (Natural Sand) Oven-dry relative densitv SSD moisture content Moisture content of sample Fineness Modulus 2.3 0.2 % 4.3 % 2.63 Coarse aggregate (crushed stone) Nominal maximum aggregate size Oven-dry relative density SSD moisture content Moisture content of sample 19 mm 2.8 1.8% 4.9 % Air entrainer: dosage rate of 0.4 g/ kg cement Summarize the mix design by providing the batch ingredients (by weight) for one cubic meter of PCC

Answer 1

US SS2

1a. S26

一 56ユ

28-day compressive strength (MPa) Water-cementing materials ratio by mass 45 40 35 30 25 20 15 Non-air-entrained concrete 0.38 0.42 0.47 0.54 0.61 0.69 0.79 Air-entrained concrete 0.30 0.34 0.39 0.45 0.52 0.60 0.70

3 Mixing water quantity' (kg/m') Specified nominal maximum size of aggregate (after CSA A23.1) (mm) Slump, mm 1014 20 28 4056 801502 I. Non-air-entrained concrete 207 25-50 (Stiff-plastic) 75-100 (Plastic) 150-175 (Flowing) Approximate en- trapped air (per cent) 199190 179166 154130113 216 205 193181 169145 124 228216 202 190178160 2.52.0 1.5 228 243 3.0 1.0 0.5 0.3 0.2 II. Air-entrained concrete 175168160150142 122 193 18417516515713 205197184174166154 181 25-50 (Stiff-plastic) 75-100 (Plastic) 150-175 (Flowing) 107 3 119 202 216 Recommended a verage total air content (per cent) Mild exposure Moderate exposure Severe exposure 4.5 6.0 7.5 4.03.5 3.0 5.55.0 4.5 7.0 6.06.0 2.5 4.5 5.5 2.0 4.0 5.0 1.5 3.5 4.5 4.0

Nominal maximum size of aggregate (after CSA A23.1) (mm) Bulk volume of oven-dry-rodded coarse aggregate (m3) Fineness modulus of fine aggregate 3.00 0.44 0.53 0.60 0.65 0.69 0.72 0.76 0.81 2.40 10 14 20 28 40 56 80 150 0.50 0.59 0.66 0.71 0.75 0.78 0.82 0.87 2.60 0.48 0.57 0.64 0.69 0.73 0.76 0.80 0.85 2.80 0.46 0.55 0.62 0.67 0.71 0.74 0.78 0.83 Notes (i) The sthe value should be multiplied by the ratio Scal Sco i creased by up to about 10 per cent e values are for aggregate of specific gravity Sca 2.68. For an aggregate having specifhic nce concrete pavements are, in general, stiffer and less workable, the above values can be Coarse aggregate volumes are bas ed on oven-dry-rodded weights obtained in accordance with ASTM C 29.