How to apply the best dry density and the best moisture content in engineering

1. The main methods used to determine the maximum dry density and moisture content by the compaction test in the actual engineering are:

1. Dry soil method (soil is not reused).

Because the compaction curve must appear peak point, it can be seen from experience, the peak value of the maximum dry density is often near the plastic limit moisture content, according to the principle of soil compaction, the peak point is the point with the smallest porosity ratio, so at least 5 samples should be prepared, and different moisture should be added respectively, of which 2 moisture content is higher than the plastic limit (increasing by 2% 3% moisture content), and 2 moisture content is lower than the plastic limit (decreasing by 2% 3% moisture content), and the stuffy material is ready for use overnight after stirring.

2. Wet soil method (soil is not reused).

The wet soil method is mainly suitable for high moisture content soil, and the sieving step can be omitted when preparing the sample, and the sample can be picked by hand to be greater than 40

mm of rough stones is acceptable. The first soil sample to maintain the natural moisture content can be used for both compaction experiments. The rest of the samples were divided into small soil blocks and air-dried separately, and the moisture content decreased by 2% to 3%.

Second, the impact of the compaction function.

Compaction refers to the fact that under the action of compaction energy, the soil particles overcome the intergranular resistance, produce displacement, and the soil particles are rearranged, so that the pores in the soil are reduced and the compactness is increased. The compaction function refers to the energy consumed per unit volume, the larger the compaction function, the smaller the optimal moisture content obtained, and the higher the corresponding maximum dry density, which shows that the compaction function is an important factor affecting the compaction effect.

Water content. With dry density, moisture content = the ratio of water in the sample to dry weight, dry density = ratio of dry weight to sample volume, the two have nothing to do with each other, if you want to calculate the relationship between the two, mainly look at the state of the substance, the detection of the moisture content of the material is very important, affecting the final application effect, Guanya SFY-20A viscogram moisture rapid tester, rapid detection of moisture, a few minutes can be completed, automatic calculation, display moisture content parameters, convenient and fast, I hope to help you.

1. First of all, soil samples should be prepared according to different moisture contents (at least 5 soil samples with different moisture contents), and stuffing for a day and night.

2. Then carry out the compaction test, and after the cluster cutting test, the soil at the top of the compacting cylinder is flattened, and the total mass of the soil in the compacting cylinder and the cylinder is weighed.

3. Calculate the quality and wet density of wet soil, and immediately take a total sample of the soil sample that has just been demolded after the compaction test to do the moisture content test.

4. Calculate the dry density of the soil sample by the measured moisture content, and after the compaction test of 5 soil samples is completely completed, the compaction curve can be obtained by using the corresponding dry density and moisture content of the 5 groups obtained, and the maximum dry density and the best moisture content can be obtained.

First of all, the approximate levels of maximum dry density and moisture content are determined empirically: the approximate levels of maximum dry density and moisture content are taken from three numerical levels, and then the orthogonal test is used to conduct the test, the target value to be studied is recorded, and then the value of the two can be determined by the analysis of variance.

Truck Truck Truck Truck Hundreds of Aspects.

Soil under the action of a certain compaction work, because of its water content.

The degree of compactness is also different. In engineering practice, it is often called the best water content that can best meet the requirements of engineering technology, so that the soil can obtain the maximum dense state, and the dry density of the soil at this time.

This is called the maximum dry density.

The optimal hole moisture content is used for the rolling control of the subgrade, and the maximum dry density is used for the detection of the rolling effect of the subgrade.

That's how it came out.

Natural moisture content: W

Wet density: P Dry density: Pd

The mass of the soil is 1, and the volume of the soil is v

The mass of soil particles is m1

The water quality is m2

m1+m2=1

p=1/vpd=m1/v

w=m2/m1

Now you should know how to derive it.

p=（m1+m2）/v，pd=m1/v=（m1+m2）/v/（（m1+m2）/m1）=p/（1+w）

m wet = m dry + m water, m water = m dry * w (moisture content), m wet = m dry + m dry * w

P wet = m wet v, p wet = (m dry + m dry * w) v, p wet = p dry + p dry * w, p dry = p wet 1 + w.

Aggregate mass = 2210kg 105 100=.

Cement quality =.

Water mass = 2210.

including the quality of cement.

Wet density = 2210 (1+.)

The mix ratio of 5:100 refers to (cement quality: dry mixture quality) In the construction, the water content of each admixture should be measured first. Draw the sum. The mass of the external water is subtracted from the sum.