Views: 0 Author: Site Editor Publish Time: 2023-03-30 Origin: Site
Abstract: When the same group is replaced by the same group, the performance of fibrin ether is mainly affected by viscosity. This article studies the effects of HPMC with different viscosity on concrete performance. The results show that the higher the viscosity of the cellulose ether, the better the concrete water retention; when the viscosity of fibin ether is lower, it will increase the slump and extension. When the viscosity of the fibin ether is higher, it will reduce the slump and the slump and Expansion; Fortoin ether with different viscosity will increase the early pressure resistance of concrete under lower doping. The lower the lower viscosity, the greater the increase in the degree of viscosity. Cellulose ether with higher viscosity will reduce the pressure resistance of the later period.
Keywords:cellulose ether; HPMC; concrete; water retention; harmonious
With the development of society, the demand for economic construction on concrete is increasing, which has exacerbated the consumption of unable to renewable resources such as gravel and gravel in the construction industry. High -quality river sand resources have become increasingly exhausted. At the same time, due to environmental protection needs The mining of river sand has made the construction industry's poor use of sand, which is more likely to cause new mixing concrete presence and poor prone, especially the concrete adhesive with large mixing liquidity, which is easy to secrete water and leave, so as Causes a series of problems such as concrete cracking. As a polymer thickener, hydroxylopyalinyl ether (HPMC) can increase the anti -hydrophilicity and anti -analysis properties of new concrete. Essence
1. Test raw materials and test methods
1.1 raw materials
Cement: China Resources PO 42.5 cement, 28D strength 54.2 MPa; flour ash: Xiamen Yicai Mansion and Coal Limited Limited; Miner Powder: Guangdong Guoxin Co., Ltd. Material: Mechanism sand, fineness of the fineness of 2.8; hydroxylopyl methyl cellulose ether: viscosity is 30,000, 100,000, and 200,000 respectively (below of HPMC -3W, HPMC -10W, HPMC -20W); outer plus agents : Polycarring acid reduction agent produced by Guangdong Kejie Industrial Co., Ltd..
1.2 Test method
Refer to the "Performance Test Method for Performance of ordinary concrete mixes" GB / T 50080 -2016, "General Power Power Test Methods" GB / T 5081-02002, "Method of Basic Performance Test Method for Building Mortar" (JGJ / T 70-209) Relevant regulations are tested. Among them, the hydrophilic test is tested with a granular sieve with a 2.36 mm of a 2.36 mm.
1.3 Test cooperation ratio
Cement: 180; flour ash: 105; mineral powder: 40; sand: 846; stone: 1033; water: 161; outer agent: 4.2.
2. Results and discussion
2.1 The effect of fibrin ether on concrete slump and extension
The effect of HPMC's viscosity and amount of doping on concrete slump and extension. After HPMC is mixed with concrete, HPMC affects the flow of concrete from two aspects. The first is to increase the viscosity of new mixing concrete, increase the viscosity Gathering makes the concrete cut force during the flow, leading to a decrease in the slump and expansion of the concrete. The second is to introduce tiny bubbles. These bubbles have a "rolling ball" effect, which improves the package. Due to the increase in adhesion, the resistance of concrete anti -ionization is greatly improved. The aggregate uniformly "suspended" in the cement slurry, reducing friction between the flow during the flow, thereby increasing the flowing aggregate and aggregate aggregate. Between friction, the slump and extension increase. The HPMC -3W is led by the second factor under low doping due to the small viscosity. ; HPMC -10W viscosity is medium. The effects of the effects of two factors under low doping are offset, the slump remains unchanged, and the first factor is dominated by the first factor when the doping is increased. High, dominate the first factor under different doping, so the slump and extension decrease.
2.2 The effect of fibrin ether to resist compressive strength
HPMC is a polymer polymer, which can bare CA (OH) 2 to increase the internal agglomeration of the cement slurry. At the same time, due to the effect of gluing and water retention, the micro -cracks of the concrete in the process of hardening are reduced The gas effect will introduce air bubbles, which causes negative effects to cause negative effects. These two functions jointly affect the compressive strength of the concrete. From the effect of HPMC on the concrete 3 D -age compressive strength, it can be seen that for the three viscosity HPMCs, the first role of the first role is to play a leading role. The early compression strength of the concrete was improved, and the maximum value was achieved at 0.025 %, and then as the amount was increased, the second role played a dominant role, and the pressure resistance intensity decreased. It can be seen from the effect of HPMC on the concrete 28 d aging staging strength, which can be seen that it also improves the later intensity of the concrete at the low doping of HPMC -3W and HPMC -10W. Then with the increase of the compressive strength of the doping amount, for the HPMC -20W, the compressive strength of the concrete has continued to decrease with the increase of the amount of mixing. The effect of comprehensive cellulose ether on the pressure resistance strength, the higher the viscosity, the lower the strength of the concrete under the same amount.
2.3 The effect of fibrin ether on water retention
The impact of HPMC on concrete water retention. The HPMC of three viscosity can reduce the loss of concrete water and improve the water retention. Under the same amount, the higher the viscosity of the HPMC, the better the water retention effect of the concrete. The slope of the three curves shows the difference between the effects of different viscosity HPMC doping on water retention. The HPMC -3W viscosity is the smallest, and the amount of doping is less than 0.050 %. The increase in water retention has increased significantly. HPMC -10W viscosity is in the middle, and the water retention properties are proportional to the doping. The HPMC -20W viscosity is the highest, with a doping of less than 0.050 %, and the water preservation effect increases greater. When the amount of mixing is greater than 0.050 %, the unit doping is increased, and the increase in water preservation effect is small.
In general, the viscosity of HPMC will affect its effect on concrete. In terms of workingality, the greater the viscosity of HPMC, the more obvious the adhesion effect of the concrete under the same amount. The more decreased, the higher the viscosity, the greater the negative impact of the compressive strength. In terms of water retention, the higher the viscosity, the better the water reservation effect. Therefore, according to different use scenarios and needs, it is especially important to choose the appropriate viscosity.