Q. Specification of Flooring for heavy repair shed?

Scope for use - For flooring for heavy repair shed, Surface hardened concrete flooring can used. In this type of flooring, a topping layer of 1.5 cm thickness and consisting of hard metal chippings, cement and a metallic based chemical (with specially treated iron filings), is laid over the base concrete to provide a tough and wear resisting surface. The base concrete should be of 1:3:6 cement concrete of thickness varying from 10 cm to 15 cm.

Surface Preparation - In the case of new concrete floors, the hard topping layer should be laid before the base course has set any surplus moisture on the base should be removed before the topping is laid.
In the case of existing concrete floor, the top surface should be hacked or roughened to obtain a good bond. The surface should be clean, free from grease, oil, dust and loose particles etc., If the base course requires levelling, a 30 mm levelling course of 1:2:4 concrete should be laid on it.

Material & Mixing Cement and the compound should be mixed thoroughly in the dry state in the ratio of 4:1 by weight. To this should be added angular crushed hard stone chips of maximum size 6 mm, in the ratio of one of the cement compound mixture to 2 of the stone chips by volume, and thoroughly mixed in dry state. Necessary quantity of clean water is added to the mixture. The amount of water used should be as low as possible consistent will the workability. For ten square meters of area, the following quantities should be used: Cement -- 110 kg
Hardening compound ... 27.5 kg

Chips ... 0. 14 m3

Laying - The hardening coat mix should be laid on the base course with sufficient material for the required thickness, and compacted with a screed or a float and the surface finished evenly. Use of neat cement or dry cement mortar on the topping to speed up the work or correct.

Curing -The surface should be wet cured for at least 14 days before it is opened to traffic.