2022 first-level construction engineer construction engineering test site concrete test sampling, notes of the first-class construction master, long press to like + forward + comment for continuous updates, click on my avatar in the Wendang version and send me a private message: 2022
1) When a continuous pouring is not larger than When the 1000m³ mix ratio of mass concrete is , the on-site sampling of concrete strength test specimens should not be less than 10 groups.
2) When a large volume of concrete of 1000-5000m³ with the same mix ratio is poured continuously at one time, the amount of concrete exceeding 1000m³ should not be less than one set of samples for every additional 500m³, and one set of samples should be taken when the increase is less than 500m³.
3) When a large volume of concrete larger than 5000m³ with the same mix proportion is poured continuously at one time, for the concrete exceeding 5000m³, the sampling should not be less than one set for every additional 1000m³. When the increase is less than 1000m³, one set should be taken.
(2) Temperature monitoring and control of large-volume concrete
1) Temperature control indicators for large-volume concrete construction should comply with the following regulations
① The temperature rise of the concrete pouring body based on the mold entry temperature should not be greater than 50°C
② The temperature difference between the inside and outside of the concrete pouring body should not be greater than 25 ℃;
③ The cooling rate of the concrete pouring body should not be greater than 2.0℃/d;
④ When the insulation cover is removed, the temperature difference between the concrete surface and the atmosphere is not greater than 20℃
2) The arrangement of monitoring points in the large-volume concrete pouring body should reflect the maximum temperature rise of the pouring body and the temperature difference between the inside and outside of the pouring body. , cooling rate and ambient temperature, the following layout can be adopted:
① The test area can be selected as a half axis of the symmetry axis of the concrete pouring body plan, and the monitoring points in the test area should be arranged in layers according to the plane
② On each test axis, the monitoring points There should not be less than 4 places
③ Along the thickness direction of the concrete pouring body, at least the surface, bottom and central temperature measuring points should be arranged, and the distance between the measuring points should not be greater than 500mm;
④ The surface temperature of the concrete pouring body should be 50mm within the surface of the concrete pouring body. Temperature;
⑤ The temperature of the bottom of the concrete pouring body should be the temperature 50mm above the bottom of the concrete pouring body.
