Civil Site Engineer Must Know

One Way Slab:
1. The ratio of longer span panel (L) to shorter span panel (B) is equal or greater than 2. Thus, L/B >= 2.
2. Main reinforcement is provided in only one direction for one way slabs.
Two Way Slab:
1. The ratio of longer span panel (L) to shorter span panel (B) is less than 2. Thus, L/B < 2.
2. Main reinforcement is provided in both the directions for two way slabs.
Minimum thickness of slab is 125 mm.
Compressive strength of Bricks is 3.5 N /mm2.
Maximum Free fall of concrete allowed is 1.50 m.
Earth work excavation for basement above 3 m should be stepped form.
Electrical conduits shall not run in column.
Dimension tolerance for cubes + – 2 mm.
In soil filling as per IS code for every 100sqm 3 sample for core cutting test should be taken.
Lapping is not allowed for the bars having diameters more than 36mm.
Minimum bars of square column is 4 bars and 6 bars for circular column.
Samples from fresh concrete shall be taken and at least a set of 6 cubes of 150mm shall be prepared and cured. 3 Cubes each at 7 days and 28 days shall be tested for compressive strength. The test results
Should be submitted to engineer for approval. If results are unsatisfactory necessary action/rectification/remedial measures has to be exercised.
Slump IS 456
1. Lightly reinforced 25 – 75 mm
2. Heavily reinforced 75 – 100 mm.
Curing Days Required
1. Super Sulphate cement: 7 days
2. Ordinary Portland cement OPC : 10 days
3. Minerals and Admixture added cement: 14 days
A set of cube tests shall be carried out for each 30 cum of concrete / each levels of casting / each batch of cement.
PH value of the water should not be less than 6.
Lapping is not allowed for the bars having diameters more than 36 mm.