A kind of low-porosity recycled concrete

Abstract

The present application discloses a low-porosity recycled concrete, which comprises the following components, measured by mass: 100 parts of cement, 400-600 parts of recycled coarse aggregate, 200-300 parts of recycled fine aggregate, 45-55 parts of fly ash, 45-55 parts of slag powder, 15-22 parts of cyclopentane oil, 4-6 parts of calcium sulfoxide, 1-3 parts of calcium hydroxide and 0.3-0.6 parts of sodium sulfate; the present application has the advantage of improving compressive strength.

Description

Technical Field

[0001] The invention relates to low-porosity recycled concrete. Background Art

[0002] Recycled concrete refers to the discarded concrete blocks that have been crushed, cleaned, and graded, and then mixed with grading in a certain proportion. At present, recycled concrete has become one of the hot topics for domestic and foreign scholars due to its advantages of energy saving, low carbon, environmental protection, and greenness. Recycled concrete began in the 1940s, mainly to solve the problem of a large amount of construction waste caused by the collapse of houses after World War II.

[0003] However, in the application process of recycled concrete, its mechanical properties face many challenges. Summary of the invention

[0004] The purpose of the present invention is to provide a low-porosity recycled concrete having the advantage of improved compressive strength.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A low-porosity recycled concrete comprises the following components, measured by mass: 100 parts of cement, 400-600 parts of recycled coarse aggregate, 200-300 parts of recycled fine aggregate, 45-55 parts of fly ash, 45-55 parts of slag powder, 15-22 parts of cyclohexane oil, 4-6 parts of ettringite, 1-3 parts of calcium hydroxide and 0.3-0.6 parts of sodium sulfate.

[0006] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of ettringite, 2 parts of calcium hydroxide and 0.5 parts of sodium sulfate.

[0007] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of ettringite, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 3 to 6 parts of PEO-PPO-PEO triblock copolymer and 1 to 3 parts of n-butyldimethylsilane.

[0008] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer and 2 parts of n-butyldimethylsilane.

[0009] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 4-6 parts of polypropylene powder and 2-4 parts of microsilica powder.

[0010] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene powder and 3 parts of microsilica powder.

[0011] Furthermore, the invention comprises the following components, measured by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene powder, 3 parts of microsilica powder, 3-6 parts of polypropylene fiber and 2-4 parts of nano-silicon dioxide.

[0012] Furthermore, the following components are included, by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene powder, 3 parts of microsilica powder, 4 parts of polypropylene fiber and 3 parts of nano-silicon dioxide.

[0013] The technical effects of the present invention are mainly reflected in the following aspects: Adding recycled coarse aggregate and recycled fine aggregate to cement is energy-saving and environmentally friendly. Adding fly ash and slag powder to it for supplementation makes the distribution more reasonable. When mixed with naphthenic oil, ettringite, calcium hydroxide and sodium sulfate and added with water, it can promote the hydration of cement clinker, effectively fill the pores, expand it, and improve the mechanical properties of concrete. At the same time, cycloalkane oil, PEO-PPO-PEO triblock copolymer and n-butyl dimethyl silane are added thereto. Cycloalkane oil and PEO-PPO-PEO triblock copolymer assist in the dispersion of n-butyl dimethyl silane, and n-butyl dimethyl silane acts with cement to improve the problems of pores and a large number of pores on the surface of concrete, thereby improving its impermeability and crack resistance. Adding polypropylene micropowder, microsilica powder, polypropylene fiber and nano-silica can further fill it, improve the internal structure and improve the frost resistance, and nano-silica can be better introduced into the interior of the concrete. DETAILED DESCRIPTION

[0014] In the embodiments of the present application, ordinary Portland cement with a strength grade of 42.5 MPa is selected as cement, Class F II fly ash produced by Mawan Power Plant is selected as fly ash, cyclohexane oil is purchased from Hengshui Aoda Chemical Rubber Co., Ltd., PEO-PPO-PEO triblock copolymer is purchased from Sigma-Aldrich F127 type, polypropylene micropowder is purchased from Lubrizol of Germany, microsilica powder is selected from 200 mesh, and polypropylene fiber is purchased from Guangdong Xinruiheng New Building Materials Co., Ltd.

[0015] Example 1: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 400 parts by mass of recycled coarse aggregate, 300 parts by mass of recycled fine aggregate, 45 parts by mass of fly ash and 45 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 50 parts by mass of water, 15 parts by mass of cyclohexane oil, 4 parts by mass of ettringite, 1 part by mass of calcium hydroxide and 0.3 parts by mass of sodium sulfate are added into the mixer, mixed and formed, and the concrete product is obtained by demolding and curing.

[0016] Example 2: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 600 parts by mass of recycled coarse aggregate, 300 parts by mass of recycled fine aggregate, 55 parts by mass of fly ash and 55 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 80 parts by mass of water, 22 parts by mass of cyclohexane oil, 6 parts by mass of ettringite, 3 parts by mass of calcium hydroxide and 0.6 parts by mass of sodium sulfate are added into the mixer, mixed and formed, and the concrete product is obtained after demolding and curing.

[0017] Example 3: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 500 parts by mass of recycled coarse aggregate, 250 parts by mass of recycled fine aggregate, 50 parts by mass of fly ash and 50 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 60 parts by mass of water, 20 parts by mass of cyclohexane oil, 5 parts by mass of ettringite, 2 parts by mass of calcium hydroxide and 0.5 parts by mass of sodium sulfate are added into the mixer, mixed and formed, and the concrete product is obtained by demolding and curing.

[0018] Example 4: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 500 parts by mass of recycled coarse aggregate, 250 parts by mass of recycled fine aggregate, 50 parts by mass of fly ash and 50 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 60 parts by mass of water, 20 parts by mass of cyclohexane oil, 5 parts by mass of ettringite, 2 parts by mass of calcium hydroxide, 0.5 parts by mass of sodium sulfate, 4 parts by mass of PEO-PPO-PEO triblock copolymer and 2 parts by mass of n-butyldimethylsilane are added into the mixer, mixed and formed, and then the concrete product is obtained by demolding and curing.

[0019] Example 5: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 500 parts by mass of recycled coarse aggregate, 250 parts by mass of recycled fine aggregate, 50 parts by mass of fly ash and 50 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 60 parts by mass of water, 20 parts by mass of cyclohexane oil, 5 parts by mass of ettringite, 2 parts by mass of calcium hydroxide, 0.5 parts by mass of sodium sulfate, 4 parts by mass of PEO-PPO-PEO triblock copolymer, 2 parts by mass of n-butyldimethylsilane, 5 parts by mass of polypropylene powder and 3 parts by mass of microsilica powder are added into the mixer, mixed and formed, and then the concrete product is obtained by demolding and curing.

[0020] Example 6: A low-porosity recycled concrete is prepared by the following method: 100 parts by mass of cement, 500 parts by mass of recycled coarse aggregate, 250 parts by mass of recycled fine aggregate, 50 parts by mass of fly ash and 50 parts by mass of slag powder are put into a concrete mixer and stirred evenly; then 60 parts by mass of water, 20 parts by mass of cyclohexane oil, 5 parts by mass of ettringite, 2 parts by mass of calcium hydroxide, 0.5 parts by mass of sodium sulfate, 4 parts by mass of PEO-PPO-PEO triblock copolymer, 2 parts by mass of n-butyldimethylsilane, 5 parts by mass of polypropylene micropowder, 3 parts by mass of microsilica powder, 4 parts by mass of polypropylene fiber and 3 parts by mass of nano-silicon dioxide are added into the mixer, mixed and formed, and then the concrete product is obtained by demolding and curing.

[0021] Compressive strength test The example was made into a cubic standard specimen with a specification of 150 mm×150 mm×150 mm, and the compressive strength of the sample after curing for 28 days was tested according to GB / T50081-2016 "Standard for Test Methods for Mechanical Properties of Ordinary Concrete". The results are shown in Table 1.

[0022] Crack resistance test The square circle crack resistance test analysis was adopted. After three days of standard curing, the concrete product was transferred to an oven at 110°C to force cracking. The crack resistance test mold molded the specimen with an outer diameter of 370±1mm, an inner diameter of 300±1mm, and a height of 140±1mm. During the period, the cracking situation was observed at all times, and the crack length and width were measured with an electronic vernier caliper. The results are shown in Table 1.

[0023] Table 1 28d compressive strength 28d total crack length / mm <![CDATA[Total cracking area of 28d / mm 2 > Example 1 52.4 57 61.2 Example 2 53.1 62 65.1 Example 3 55.2 53 58.2 Example 4 56.7 44 43.1 Example 5 58.2 36 34.3 Example 6 59.8 29 30.5 Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A low-porosity recycled concrete, characterized in that: Calculated by mass, it includes the following components: 100 parts of cement, 400-600 parts of recycled coarse aggregate, 200-300 parts of recycled fine aggregate, 45-55 parts of fly ash, 45-55 parts of slag powder, 15-22 parts of cyclohexane oil, 4-6 parts of ettringite, 1-3 parts of calcium hydroxide and 0.3-0.6 parts of sodium sulfate.

2. The low-porosity recycled concrete according to claim 1, characterized in that: The composition includes the following components by weight: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of ettringite, 2 parts of calcium hydroxide and 0.5 parts of sodium sulfate.

3. The low-porosity recycled concrete according to claim 2, characterized in that: The invention comprises the following components by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of ettringite, 2 parts of calcium hydroxide, 0.5 part of sodium sulfate, 3-6 parts of PEO-PPO-PEO triblock copolymer and 1-3 parts of n-butyldimethylsilane.

4. The low-porosity recycled concrete according to claim 3 is characterized in that: The invention comprises the following components by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer and 2 parts of n-butyldimethylsilane.

5. The low-porosity recycled concrete according to claim 4, characterized in that: The material comprises the following components in parts by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 4-6 parts of polypropylene powder and 2-4 parts of microsilica powder.

6. The low-porosity recycled concrete according to claim 5, characterized in that: The composition includes the following components by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene powder and 3 parts of microsilica powder.

7. The low-porosity recycled concrete according to claim 6, characterized in that: The invention comprises the following components by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene powder, 3 parts of microsilica powder, 3-6 parts of polypropylene fiber and 2-4 parts of nano-silicon dioxide.

8. The low-porosity recycled concrete according to claim 7, characterized in that: The material comprises the following components by mass: 100 parts of cement, 500 parts of recycled coarse aggregate, 250 parts of recycled fine aggregate, 50 parts of fly ash, 50 parts of slag powder, 20 parts of cyclohexane oil, 5 parts of calcium aluminate, 2 parts of calcium hydroxide, 0.5 parts of sodium sulfate, 4 parts of PEO-PPO-PEO triblock copolymer, 2 parts of n-butyldimethylsilane, 5 parts of polypropylene micropowder, 3 parts of microsilica powder, 4 parts of polypropylene fiber and 3 parts of nano-silicon dioxide.