30x40 Concrete Slab Calculator

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Slab Shape:

Select Unit for All Dimensions:

Select Mix:

Mix ratio: (Cement:Sand:Aggregate)

Quantity:

Concrete Volume (ft³):

Concrete Volume (m³):

Concrete Volume (yd³):

Concrete Weight (kg):

Concrete Density = 2400 kg/m³

Wet Volume of Mix (m³):

Amount of Cement Required (m³):

No. of Cement Bags (50 kg/bag):

Amount of Sand Required (m³):

Sand in Kg:

Sand in Tons:

Amount of Aggregate Required (m³):

Aggregate in Kg:

Aggregate density : 1.5 Ton/cuyd

Aggregate in Tons:

Volume Calculation

Thickness	Volume (Cubic Feet)	Volume (Cubic Yards)
4 inches	400	14.81
6 inches	600	22.22

Cost Estimate

Thickness	Concrete Cost ($125-$150 per cubic yard)	Total Cost Estimate (Including Labor)
4 inches	$1,851 - $2,222	$7,200 - $12,000
6 inches	$2,778 - $3,333	$10,800 - $16,000

Preparation

Design Confirmation: Before construction, confirm the design and dimensions of the concrete slab to ensure compliance with design requirements.
Site Cleanup: Clean the construction site, ensure that the foundation bearing capacity meets the requirements, and set up construction signs and safety measures.

Formwork Installation

Formwork Material: Forms are typically made of wood or metal and should be customized according to the shape and size of the slab.
Secure Installation: Forms should be installed securely and evenly. There should be no gaps between forms to prevent concrete leakage.
Debris Removal: Before pouring, be sure to clean debris, dirt, grease, and other impurities in the forms to avoid affecting the adhesion of the concrete.

Reinforcement Layout

Reinforcement Quality: Ensure that the quality of the reinforcement meets relevant standards.
Uniform Layout: Lay and fix the reinforcement mesh or reinforcement bars on the forms according to the design requirements of the slab.

Concrete Pouring

Concrete Quality: Ensure the quality of the concrete, including the correct proportions of cement, sand, aggregate, and water.
Pouring Method: When the pouring height is greater than 2 meters, use a chute or tremie for discharging to reduce impact and prevent form deformation or damage. Concrete should be poured and vibrated simultaneously, with vibration insufficient to prevent air bubbles in the concrete.
Pouring Speed: Concrete must be poured within 5 hours (from the time of dispatch), and the interval between two pours should not exceed 1.5 hours to prevent the formation of cold joints.
Vibration Time: The vibration time should be sufficient for the concrete surface to appear creamy, with no bubbles and no subsidence. Vibrators should be evenly spaced, with a movement distance not exceeding 40 cm, to ensure no missing or excessive vibration.

Curing and Formwork Removal

Curing Measures: After pouring, appropriate curing measures should be taken, including covering with wet cloths, spraying water, shading, etc., to prevent premature drying and cracking of the concrete. The typical curing period for concrete is 28 days.
Formwork Removal Time: Forms can be removed after the concrete reaches sufficient strength. When removing forms, be careful to avoid damaging the newly poured concrete slab.

Other Precautions

Observe Forms and Reinforcement: During pouring, pay attention to observing the condition of forms, supports, and reinforcement. If deformation or displacement is found, immediate adjustment or handling is required.
Bleeding Water Treatment: During pouring, if excessive bleeding water appears on the surface, it should be properly drained, but the mortar must not be taken away.
Lighting Equipment: Sufficient lighting equipment is required for pouring at night.
Safety Measures: The construction site should be kept safe and tidy, following building codes and safety operation requirements for construction.