1. A process method for improving mechanical properties of coral aggregates based on a pre-slurry wrapping method is characterized by comprising the following specific steps:

s1: preparing cement, silicon powder, coral aggregate and mixed water;

s2: taking a proper amount of coral aggregates, and measuring the apparent density, water absorption and crushing index of the coral aggregates;

s3: taking coral aggregates to be wrapped with pulp, cleaning and drying;

s4: preparing slurry wrapping slurry with the water-to-glue ratio of 0.65 and 0.9 by using cement, silicon powder and water, wherein the mixing amount of the silicon powder is 5 percent, 7 percent and 9 percent of the using amount of the cement respectively;

s5: adding the coral aggregates cleaned and dried in the step S3 into the prepared slurry coating slurry, slowly stirring to ensure that the slurry coating is uniform, and coating the slurry for 10 minutes at normal temperature;

s6: taking out the coral aggregates wrapped with the pulp, dispersing and placing the coral aggregates on a porcelain plate, and standing for 7 days and 14 days at normal temperature;

s7: measuring the apparent density, water absorption and crushing indexes of the mortar-coated coral aggregates;

s8: and comparing the apparent density, water absorption and crushing indexes of the coral aggregate wrapped with the pulp with corresponding data of the original coral aggregate, and analyzing the effect of coral aggregate pre-wrapped with the pulp.

2. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S1, the cement is composite portland cement p.c 42.5; the SiO2 content in the silicon powder is more than 90 percent; the coral aggregate is mostly rod-shaped, and the particle size is 30mm-60 mm; the mixed water is fresh water.

3. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S2, the coral aggregates are cleaned to remove impurities; soaking the coral aggregates in fresh water for 24 hours in order to make the coral aggregates fully absorb water to measure the quality of the coral aggregates in a water-saturated state; then, measuring the mass of the coral aggregate in water by adopting a static water balance; taking out the coral aggregates, placing the coral aggregates on a porcelain plate, wiping the surface of the porcelain plate with wet towel, and measuring the surface drying quality of the aggregates; placing the coral aggregate into an oven, drying for 10 hours at the temperature of 100 +/-5 ℃, taking out the aggregate, and measuring the dried quality of the aggregate; and calculating the apparent density and water absorption of the coral aggregate.

4. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 3, wherein: step S2, the same batch of the aggregate is taken to fill a metal cylinder with the capacity of 1L, the metal cylinder is weighed by balance and then poured into a stone crusher, a compression column is covered on the metal cylinder and put into a press machine for a crushing test, and the compression is stopped when the pressure value reaches 300 kN; taking out the coral aggregates in the stone crusher, pouring the coral aggregates into a porcelain plate, sieving the porcelain plate by using a square-hole sieve of 2.36mm, weighing the mass of the sieved coral aggregates, and determining the crushing index value of the coral aggregates.

5. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in the step S3, the coral aggregates to be coated with the slurry are cleaned and dried for 3 hours for later use.

6. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S4, composite portland cement P.C42.5 and silicon powder are adopted as cementing materials to prepare slurry-coated slurry, wherein the mixing amount of the silicon powder is respectively 5%, 7% and 9% of the cement amount; the water-to-glue ratio was 0.65 and 0.9.

7. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S5, the cementitious material, i.e., the composite portland cement p.c42.5, and the silicon powder are mixed for 1 minute; adding stirring water and stirring for 1 minute; and adding the coral aggregates washed and dried in the step S3, and stirring for 2 minutes to ensure that the slurry is fully contacted with the coral aggregates, wherein the time is 10 minutes.

8. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S6, taking out the coral aggregates wrapped with the pulp, and then distributing the coral aggregates on a porcelain plate as far as possible; standing at room temperature for 7 days and 14 days.

9. The process method for improving the performance of the coral aggregates based on the pre-coating method as claimed in claim 1, wherein: in step S7, the slurry-wrapped coral aggregate is immersed in fresh water for 24 hours, and then the apparent density, water absorption, and crush index of the slurry-wrapped coral aggregate are measured in accordance with step S2.

Background

It has been shown by prior studies that when the density of coral aggregates is comparable to that of ordinary aggregates, the coral aggregates become the weakest zone in the concrete, rather than the aggregate-matrix interface transition zone in traditional concrete; when the density of the coral aggregate is far less than that of the common aggregate, the 28-day compressive strength of the concrete is still low even if the water-cement ratio is small.

The principle of the pre-coating method is that the aggregate is pre-coated by preparing slurry coating slurry with proper mixing proportion, so that the apparent density of the coral aggregate is improved, and the pores of the aggregate and the water absorption and crushing indexes of the aggregate are reduced. However, the coral aggregates have more micropores, communicated and tortuous pores, and slurry is not easy to enter the aggregates, so that the slurry wrapping effect is influenced. Thus, it is necessary to investigate the pre-slurry wrapping method to determine a better mix ratio of slurry; meanwhile, considering the actual situation of engineering construction, the better cementing time needs to be determined. Both of the two methods are the key for improving the performance of the coral aggregate by adopting a pre-coating method.

Disclosure of Invention

The invention aims to provide a technological method for improving the performance of coral aggregates based on a pre-coating method, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a process method for improving the performance of coral aggregates based on a pre-slurry wrapping method comprises the following specific steps:

s1: preparing cement, silicon powder, coral aggregate and mixed water;

s2: taking a proper amount of coral aggregates, and measuring the apparent density, water absorption and crushing index of the coral aggregates;

s3: taking coral aggregates to be wrapped with pulp, cleaning and drying;

s4: preparing slurry wrapping slurry with the water-to-glue ratio of 0.65 and 0.9 by using cement, silicon powder and water, wherein the mixing amount of the silicon powder is 5 percent, 7 percent and 9 percent of the using amount of the cement respectively;

s5: adding the coral aggregates cleaned and dried in the step S3 into the prepared slurry coating slurry, slowly stirring to ensure that the slurry coating is uniform, and coating the slurry for 10 minutes at normal temperature;

s6: taking out the coral aggregates wrapped with the pulp, dispersing and placing the coral aggregates on a porcelain plate, and standing for 7 days and 14 days at normal temperature;

s7: measuring the apparent density, water absorption and crushing indexes of the mortar-coated coral aggregates;

s8: and comparing the apparent density, water absorption and crushing indexes of the coral aggregate wrapped with the pulp with corresponding data of the original coral aggregate, and analyzing the effect of coral aggregate pre-wrapped with the pulp.

Preferably, in step S1, the cement is composite portland cement p.c 42.5; the SiO2 content in the silicon powder is more than 90 percent; the coral aggregate is mostly rod-shaped, and the particle size is 30mm-60 mm; the mixed water is fresh water.

Preferably, in step S2, the coral aggregates are washed to remove impurities; soaking the coral aggregates in fresh water for 24 hours in order to make the coral aggregates fully absorb water to measure the quality of the coral aggregates in a water-saturated state; then, measuring the mass of the coral aggregate in water by adopting a static water balance; taking out the coral aggregates, placing the coral aggregates on a porcelain plate, wiping the surface of the porcelain plate with wet towel, and measuring the surface drying quality of the aggregates; placing the coral aggregate into an oven, drying for 10 hours at the temperature of 100 +/-5 ℃, taking out the aggregate, and measuring the dried quality of the aggregate; and calculating the apparent density and water absorption of the coral aggregate.

Preferably, in step S2, the same batch of aggregates is filled with a metal cylinder with a volume of 1L, weighed by balance and poured into a stone crusher, covered with a compression column and put into a press machine for a crushing test, and the pressure is stopped when the pressure value reaches 300 kN; taking out the coral aggregates in the stone crusher, pouring the coral aggregates into a porcelain plate, sieving the porcelain plate by using a square-hole sieve of 2.36mm, weighing the mass of the sieved coral aggregates, and determining the crushing index value of the coral aggregates.

Preferably, in step S3, the coral aggregates to be coated with the slurry are washed and then dried for 3 hours for further use.

Preferably, in step S4, the slurry wrapping slurry is prepared by using composite portland cement p.c42.5 and silica powder as gelling materials, wherein the silica powder content is 5%, 7%, and 9% of the cement content respectively; the water-to-glue ratio was 0.65 and 0.9.

Preferably, in step S5, the cement, i.e., the composite portland cement p.c42.5 and the silicon powder, is mixed for 1 minute; adding stirring water and stirring for 1 minute; and adding the coral aggregates washed and dried in the step S3, and stirring for 2 minutes to ensure that the slurry is fully contacted with the coral aggregates, wherein the time is 10 minutes.

Preferably, in step S6, the coral aggregates coated with the pulp are taken out and then placed on the porcelain plate as dispersedly as possible; standing at room temperature for 7 days and 14 days.

Preferably, in step S7, the slurry-wrapped coral aggregate is immersed in fresh water for 24 hours, and then the apparent density, water absorption, and crush index of the slurry-wrapped coral aggregate are measured in accordance with step S2.

Compared with the prior art, the invention has the beneficial effects that:

after the coral aggregates are pre-coated with the slurry, the mechanical properties of the coral aggregates are improved to a certain extent; compared with the traditional mode of adding a reinforcing agent and fibers into the coral aggregate concrete, the method has the advantages of simple operation, low cost and good effect of reinforcing the mechanical property of the coral aggregate, and provides a new idea for the practical application of engineering in the future; the invention provides a technological method for enhancing the mechanical property of coral aggregates based on a pre-slurry wrapping method, and has important significance for taking the coral aggregates as concrete aggregates and applying the concrete aggregates to ocean island reinforced concrete engineering construction.

Drawings

FIG. 1 shows an operation flow of measuring mechanical property data of coral aggregates;

FIG. 2 is a schematic view of a coral aggregate precoating slurry process.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: a process method for improving the performance of coral aggregates based on a pre-slurry wrapping method comprises the following specific steps:

s1: preparing a pre-coated slurry experimental material which comprises cement, silicon powder, coral aggregate and mixed water (fresh water);

s2: taking appropriate amount of coral aggregates, grouping, measuring apparent density, water absorption and crushing index of each group of aggregates according to figure 1, and measuring results are shown in tables 1 and 3;

s3: taking coral aggregates to be wrapped with pulp, cleaning and drying;

s4: respectively preparing slurry wrapping slurry with water-to-gel ratios of 0.65 and 0.9 according to a figure 2, wherein the mixing amount of the silicon powder is respectively 5%, 7% and 9% of the cement amount (a part of the cement is replaced by the silicon powder);

s5: adding the coral aggregates cleaned and dried in the step S3 into the prepared slurry coating slurry, slowly stirring to ensure that the slurry coating is uniform, and coating the slurry for 10 minutes at normal temperature;

s6: after the aggregate is pre-coated with the slurry, taking out the aggregate, dispersing the aggregate on a porcelain plate (the aggregate particles are prevented from being cemented into blocks as much as possible), and standing for 7 days and 14 days at normal temperature;

s7: measuring the apparent density, water absorption and crushing index of the coral aggregate cemented for 7 days or 14 days in step S6 according to FIG. 1;

s8: comparing the apparent density, water absorption and crushing index of the coral aggregates wrapped with the pulp with the corresponding data of the original coral aggregates, and analyzing the effect of coral aggregates pre-wrapped with the pulp, wherein the specific results are shown in tables 1, 2 and 3.

TABLE 1 apparent Density and Water absorption of Pre-grouted coral aggregates with a Water to gel ratio of 0.65

TABLE 2 apparent density and Water absorption of Pre-grouted coral aggregates with a Water to gel ratio of 0.90

TABLE 3 crushing index of Pre-wrapped grouted coral aggregates

In step S1, the coral aggregates used in the experiment should be the same batch, and it should be ensured that the cement and silicon powder are within the shelf life and are not affected with moisture and hard lumps.

In step S2, the mechanical properties of the coral aggregates are measured according to fig. 1: firstly, cleaning coral aggregates to remove impurities; soaking the coral aggregates in fresh water for 24 hours in order to make the coral aggregates fully absorb water to measure the quality of the coral aggregates in a water-saturated state; then, measuring the mass of the coral aggregates in water by using a static water balance, wherein the aggregates in the net basket are required to be completely immersed in the water during measurement, and the net basket cannot touch the wall of the water barrel; taking out the coral aggregates, placing the coral aggregates on a porcelain plate, wiping the surface of the porcelain plate with wet towel, and measuring the surface drying quality of the aggregates; placing the coral aggregate into an oven, drying for 10 hours at the temperature of 100 +/-5 ℃, taking out the aggregate, and measuring the dried quality of the aggregate; and calculating the apparent density and water absorption of the coral aggregate.

Filling a metal cylinder with the capacity of 1L with the same batch of aggregate, weighing the aggregate by balance, pouring the weighed aggregate into a stone crushing instrument, covering a compression column, putting the compression column into a press machine for a crushing test, and stopping pressurizing when the pressure value reaches 300 kN; taking out the coral aggregates in the stone crusher, pouring the coral aggregates into a porcelain plate, sieving the porcelain plate by using a square-hole sieve of 2.36mm, weighing the mass of the sieved coral aggregates, and determining the crushing index value of the coral aggregates.

In step S3, the coral aggregate to be coated with the pulp is cleaned and then dried for 10 hours at the temperature of 100 +/-5 ℃;

in step S4, adding the composite Portland cement P.C42.5 and the silicon powder into a stirring pot of a cement mortar stirrer in sequence, starting the machine, and stirring for 1 minute at low speed; after the machine is stopped, adding the mixing water (fresh water), and then starting the machine to mix for 1 minute at a constant speed.

In step S5, the washed and dried coral aggregate is added into the prepared slurry coating slurry, the slurry and the aggregate are fully contacted by stirring at low speed for 2 minutes, and then the slurry is coated for 10 minutes at normal temperature.

In step S6, the coral aggregates after slurry coating are filtered out by using a wire mesh (the diameter of the mesh opening is less than 20mm), and then are dispersedly placed on a porcelain plate with the specification of 40mm × 60 mm.

In step S7, after the mortar-coated coral aggregates are left to stand at room temperature for 7 days and 14 days, the apparent density, water absorption and crushing index at that time are measured according to the operation flow of fig. 1; before measuring the quality of each group of the coral aggregates wrapped with the pulp in water, soaking the coral aggregates wrapped with the pulp in fresh water for 24 hours, wherein the height from the water surface to the highest point of the aggregates is 20 mm; when drying, putting all the groups of coral aggregates wrapped with the pulp into a drying oven at the same time, drying for 10 hours at the temperature of 100 +/-5 ℃, taking out the coral aggregates wrapped with the pulp, respectively putting the coral aggregates wrapped with the pulp into plastic bags with labels, sealing the plastic bags (avoiding the influence of moisture in the air), cooling the plastic bags, taking out the plastic bags, and measuring the quality of the plastic bags.

In step S8, the apparent density, water absorption and crushing index of the coral aggregate wrapped with the pulp are compared with the corresponding data of the original coral aggregate, and the effect of coral aggregate pre-wrapped with the pulp is analyzed.

Experiments prove that according to the process method for improving the performance of the coral aggregate based on the pre-coating method, provided by the invention, different water-glue ratios (0.65 or 0.9), silicon powder mixing amounts (5%, 7% or 9%) and gluing time (7 days or 14 days) have different influences on the performance improvement of the coral aggregate based on the pre-coating method, and the following conditions can be referred to:

(1) after the coral aggregates are pre-coated with the slurry, the apparent density of the coral aggregates is improved on the whole; the water absorption is reduced from 15 to 16 percent to 10 to 12 percent; the 14-day crushing index is reduced from 43-45% to 37-41%. Therefore, the mechanical property of the coral aggregate precoated pulp is improved;

(2) when the water-glue ratio is the same (0.65 or 0.9) and the silicon powder mixing amount is the same (5%, 7% or 9%), the performance of the coral bone material wrapped with the paste within 14 days of the paste wrapping and gluing time is better improved;

(3) when the mixing amount of the silicon powder is the same, the apparent density of the 0.9 water-gel ratio pre-coated coral aggregate is improved, and the water absorption rate reduction effect is more remarkable than that of the 0.65 water-gel ratio pre-coated coral aggregate;

(4) under the condition of 14 days of slurry wrapping and cementing time, when the mixing amount (5%, 7% or 9%) of silicon powder is the same, the crushing index of the 0.9 water gel-precoated coral aggregate is obviously reduced compared with that of the 0.65 water gel-precoated coral aggregate.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.