Hot Weather Concreting
Concrete should not be mixed or placed when the temperature of the air curtain on the site is 40 ° C or more, unless the contractor has demonstrated special measures to ensure that the concrete is placed successfully compacted and hardened. The temperature of the fresh concrete shall not exceed 32 ° C, unless it is shown that at a higher than the strength and durability of concrete structures temperature is not compromised. The building will remain in the shade for at least 4 hours before concreting. All metal frame, concrete or other material of high thermal capacity is cooled with water before casting the concrete against them. Only water that meets the requirements of mixing water is used for washing and cooling of forms, etc.
GRP Linings
Chemical resistant waterproof lining is formed with a minimum thickness of 7 mm of glass reinforced plastic ( GRP ) laminate . GRP laminate coating comprises a layer of at least 4 mm thick , 29 percent of "E" glass to 71 percent base layer rich in resin , and a resin -rich outer layer of 2 mm thick ( layer in contact with the liquid ) which is a vinyl ester resin approved at least two layers of assembly of a fiberglass mat 90 percent to 10 percent of resin " C " in a glass weight "C" report. The glass coating is formed to correspond to the required dimensions and configurations , as shown in the drawings , and is installed in the clauses , as required for proper placement of concrete and assembly techniques on the ground GRP . Each GRP liner also be equipped with pipe openings pre - molded , so that good adhesion can be obtained between the liner and the pipe GRP otherwise , and as shown in the drawings . All joints glued GRP field must meet the minimum requirements of the shirt and equipped so that the connection is tight and without power loss occurs through the joint. The joint strips are applied in the field of at least 100 mm wide, 6 mm thick laminate made of a 71 percent content of vinyl ester resin and 29 percent glass "E " .
In the inner faces of the manholes or other retention structures wastewater sealing strips are applied to the liner portion GRP concrete . Immediately prior to acceptance by the employer and after leakage inspection of a set of additional bands is fixed inside the shirt GRP .
Coatings have GRP prefabricated connecting tongues ( concrete pins ) , divided into 100 mm long strips of GRP or GRP bound round pin adjacent the side of each individual panel of glass fiber, not more than 500 mm x 500 mm approximate distance . The shape of each leg must be such as to produce a secure seal in the concrete cast in place such that the glass coating is held firmly in place , in contact with the concrete surface , reducing any tendency of the layer to be unlimited and "float" away from the concrete. The coating prefabricated glass fiber was prepared properly and carefully managed so that excessive fluctuations , breaking, or cracking of the coating does not occur during handling , installation and concrete pouring .
A non-slip finish is placed on horizontal surfaces benches , platforms and waypoints dusting the rolling surface with silica sand when the resin has a soft gel . Arena surplus is then brushed at least 24 hours later.
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