Concrete test block making problem 15

If you are doing standard culture test blocks, according to the specification, you need to make test blocks in two times according to the date of your two pourings; If you are doing homotrophic or impermeable test blocks, in fact, you only need to choose a group of test blocks at one time. In case your pool is a unit project (probably not, haha), unfortunately, whether it is a standard culture test block or a homotrophic test block or an impermeability test block, you need to make up 3 groups (standard culture needs to be done twice, and the same culture can be done once or twice) in order to evaluate the compressive strength of concrete in the future. Of course, these are all norms, in fact, if it is some small non-stressed components, if the owner and the supervisor agree, as long as one group is enough, or even one group is exempted.

Just do it once, the test block is according to each structure or each concrete work shift, you can do it once regardless of the type.

The specification requires that when the concrete is poured, when a continuous pouring does not exceed 1000m3, the concrete 100m3 sampling of the same mix ratio is not less than once, and a group is also taken when it is less than 100m3. When a continuous pouring exceeds 1000m3, the concrete of the same mix ratio shall be sampled not less than once every 200m3;

Depending on your situation, the right thing to do is to do two sets, one for the first time and one for the second time.

According to the requirements of the superintendent is to do the test block as long as it is to hit the concrete, but it is OK to do it once in the same part when doing the data, in fact, many test blocks are made on the construction site now, most of them are bought commercial mixing station test blocks, and many of the pressure tests they do are unqualified. If you don't want to do it twice, you can tell the supervisor to do the same part once, anyway, it is the same grade of concrete, just do two groups at a time.

The first step is to prepare the work, and prepare for the mold test: the first thing is to clean up the mold test, if it is not clean, it will affect the quality of the overall concrete. Then the inner surface is evenly brushed with the coating agent, which can also be replaced by waste engine oil. It is also an essential step.

In the second step, a piece of tissue paper is placed on the bottom hole, which is convenient when removing the film with the compressor. Without this layer of tissue paper, it is easy to form during demolding, or it is laborious to demold. Causing half-ass.

The third step, use an iron shovel to connect the concrete from the mouth of the tanker that is discharging, put it into the mold test little by little, pay attention to the 1 3 of the overall space for each test mold, and then vibrate with an iron rod appropriately to make the material flat. And so on until it is done.

The fourth and last step is to put the installed test blocks in the curing box for curing. After the curing is completed, the production of the concrete test block is over. Removal from the curing chamber is the final product. That's it.

1. Mold preparation is necessary, and the release agent should be brushed inside (oil can also be removed, but ensure that there will be no chemical reaction with concrete); When forming with a vibrating table, the concrete should be put into the mold at one time, and the spatula should be slightly inserted and pounded along the inner wall of the test mold when loading, and the mixture should be higher than the upper mouth of the test mold, and the mold should be prevented from beating freely on the vibrating table when vibrating, and the vibration should continue until the concrete surface is slurryed, and the excess concrete should be scraped off and smoothed with a spatula and prepared for curing work; With manual tamping is to divide the mixture into the mold twice, the thickness of each layer of charging is roughly equal, the steel tamper used for tamping is 600mm long, the diameter is 16mm, the end should be rounded, each layer of ramming data should be determined by the cross-sectional area of the specimen, generally the number of insertions per 100 square centimeters of cross-sectional area should not be less than 12 times, scrape off the excess concrete and scrape flat with a spatula after the completion of the insertion, and start curing. Building Construction Manual 4th Edition See for yourself.

Certainly, two loads, three checks, four tests, five selections, six mixing, seven pounding, eight rows, nine covers, ten raising,

The first step, preparation, mold trial preparation: clean the mold test, evenly brush the inner surface with the coating agent (can also be replaced by waste engine oil), and put a piece of tissue paper on the bottom hole, (this is for the convenience of decoating with a compressor); You can also leave it alone, and you have to use ingenuity to knock it when you remove the mold.

The second step, with an iron shovel from the mouth of the tanker that is being discharged, put into the test mold, put 1 3 in each test mold, vibrate with an iron rod, and so on, until it is completed.

The third step is to put the test block in the curing box for maintenance.

You guess hahaha don't tell you.

Certainly: designate personnel posts, test operators should not change frequently, choose comrades with certain technical quality and a strong sense of responsibility to operate.

Second installation: refers to the disassembly, slag removal and assembly process of the test block, check its fastening degree and size error, the release agent should be evenly brushed, and the precipitated oil stains should be wiped clean. The mold trial adopts the standard mold trial.

Three checks: Before the production of concrete pure soil, the test personnel should carefully check and verify whether the raw materials and mix ratio are consistent with the corresponding test blocks, and urge the operators to input relevant data according to the design requirements.

Four tests: When the concrete pure soil leaves the factory and after entering the construction site, its slump should be tested separately.

Five selections: Before making the test block, the concrete pure soil clinker should be selected together according to the requirements of "submission for inspection" and the construction and supervision of the tripartite visa.

6. Mixing: After the sample size of the test block is selected, it should be mixed evenly by hand for the second time.

Seven pounding: refers to the clinker is divided into two layers into the mold and compacted, and the pounding rod is inserted and pounded in turn from the outside to the inside. Add some clinker while inserting.

Eight rows: Repeatedly interspersed with a flat shovel while inserting and pounding to remove the air inside the test block. When the surface of the test block is collected, pay attention to the fullness of the slurry to prevent the concave condition caused by the plastic deformation of the concrete pure soil.

Nine covers: After the test block is formed, it is often placed in situ or in the open air before the final setting, in order to prevent the internal water from evaporating and affecting the hydration rate of the cement, the test block should be covered tightly with black plastic cloth in time.

Ten maintenance: refers to the test block after hardening and mold removal, should be sent to the standard curing room in time for maintenance (**, the use of both parties to jointly supervise the implementation).

Let's take a look at the relevant test standards.