Usually standard curing time for a 28-day delivery, three days ahead of time can not be more than 28 days, or to rebound, count overage of the same curing condition at 600 ° or more, usually from the day of pounding the concrete when the temperature began to accumulate scene, it can go up to 600 degrees sent. Condition number of days with not less than 14 days and not more than 90 days. The following is a sample batch project the number of samples per test block 1. Concrete Compressive mixing 100 and not more than 100m3 of concrete mix with less than 1 second 2. Each work shift mixing of the concrete mix with less than 100 3. when at least once a continuous casting played 1000m3, the same mix of concrete not less than once every 4 200m3 each floor, the same mix of concrete not less than once every 5 Pile Concrete pouring 50m3, smaller than 50m3 of piles, each pile must have a group of not less than 1 6. each batch of concrete form removal test at least one group of diaphragm wall 7. the excavation, each 50m3 each groove section or not less than 1 8. ground engineering construction of concrete test blocks for each layer (inspection Lot) per 1000m2 sampling of not less than 1, each additional 1000m2 shall be taken by 1, by less than 1000m2 1000m2 meter. When changing the mixing ratio, a corresponding increase in the sampling frequency and the first use of concrete mix opening identifying at least one group
Concrete acceptance specifications and requirements 1, before the opening of concrete, the use of cement, sand, stone and other materials must be tested with a test. Raw materials before using. After opening the site to extract the raw material must require concrete specimens (Party present). 2, concrete construction under certain conditions as much as possible the overall situation watering, special circumstances must be positioned indwelling construction joints according to design requirements, while continuing construction Peng expansion construction joints must be treated like about the norm. Concreting within 12 hours after the designated persons must cover and conservation. 3, sand, stone and clay content must be strictly controlled: Sand clay content: When the concrete strength ≥C30 when clay content ≤3% when the concrete strength grade x26lt;C30 when the clay content, clay content ≤5% stone: When the concrete strength ≥C30 when clay content ≤1% clay content ≤2% 4 when concrete strength grade C25-C15, the amount of water strictly concrete: Ensure the workability of concrete, slump, slump concrete field sampling tests qualified, it is strictly prohibited. He said the pound used should always check. 5, strict quality-situ concrete to avoid the common problem occurs: Exposed tendons, cellular, holes, clip ballast, loose, cracks, missing edge off angle, not straight edges, uneven warping, burrs ribs, peel from the sand, deformation Inflation ran mold displacement. Then hew false and so on.
Earthworks and backfill quality requirements 1, the substrate can not be over-excavation, exceeds the base level, there Overbreak place, design units must obtain the consent of the construction team can not be treated privately. (Graves, pits, wells and other soft soil) 2, when the rainy season, the foundation trench, pit bottom to reserve 30cm soil layer, when playing in front of a concrete pad to dig to the design elevation to prevent clear trough over elevation. 3, after the completion drill exploration should be well marked, to protect the solder hole, after design, surveying acceptance, drill holes filling sand. Each fill when filling sand about 30cm, or reinforced with a wooden tamping stick once, drill hole filling sand must be dense. 4, priority use of excavated backfill the original soil. Rainy season, the best accumulation of excavated soil cover to prevent rain water content is too high. Not contain organic impurities (roots, roots, etc.) should be sifted before use, the particle size of not more than 5 cm water to meet the requirements. 5, backfill should be layered spread out, when using breaststroke ramming machine compacted thickness of each layer of soil spread of not more than 25 cm (artificial ramming not more than 20 cm). Prohibited the filling of vehicle thick or pour directly into the soil trough. It prohibited the use of "water ram." Topical artificial ram, but also to ensure quality.
