General Performance of Sulfonic Group Modified Polycarboxylate-Type Superplasticizer

2011 ◽  
Vol 396-398 ◽  
pp. 2375-2378
Author(s):  
Yan Lin Sun ◽  
Hong Wang ◽  
Hui Xiang Du ◽  
Yun Hua Huang

The polycarboxylate-type superplasticizers (PCS) modified by sulfonic group were prepared. The influence of sulfonic group content on the performance of cement admixtures when using sulfonic group modified PCS was discussed. Some physical properties such as dispersion, cement paste fluidity, mortar fluidity, compressive strength ratio and flexural strength ratio were investigated. The results show that when using PCS with sulfonic group content 20%~25% (mol/mol of total carboxyl group), the dispersion and fluidity of concrete can be distinctly improved, meanwhile the strength properties can be maintained.

2019 ◽  
Vol 10 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Markéta Hošťálková ◽  
Nikola Vavřínová ◽  
Veronika Longauerová

The gypsum is one of the most often used materials in the civil engineering. Very often it is applied in the form of plasterboards without any reinforcement, for example, cladding boards are unusable as supporting construction. To improve the mechanical properties of plasterboards, fibrous materials such as cellulose or glass fiber are added. Reinforcement of gypsum with fibers improves in particular the flexural and shear strength. The main purpose of the research is to clarify whether natural wooden fibers could be used as the reinforced of composite gypsum building materials. Wooden fibers are used as a blown or board thermal insulation. This article presents the results of tests aimed at determining the mechanical and physical properties of gypsum composite reinforced with wooden fibers. The effect of the reinforcement on the strength properties as a compressive strength, flexural strength was verified on a series of test specimens. The results of the tests have shown that the reinforcing of gypsum composite has an impact on the mechanical-physical parameters.


2020 ◽  
Vol 302 ◽  
pp. 101-106
Author(s):  
Siriphorn Rabma ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong

The aim of this research was to study the properties of cement reinforced with coconut fiber. The coconut fiber addition that uses in this research were 5, 10 and 15% by weight of cement. The cement paste and coconut fiber were mixed together and packed into an iron mold. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the water bath at 3, 7 and 28 days. After that, the physical properties i.e. water absorption and density were examined. The microstructure was characterized by scanning electron microscopy (SEM). The results showed the surfaces of the coconut fibers were not smooth, spread with nodes and irregular stripes, which is covered with substances and other impurities. The compressive strength and flexural strength were also investigated. From the results, the mechanical properties were decreased with increasing coconut fiber content due to reducing density and higher porosity and water absorption compared to non-fiber cement paste and physical properties of fiber had been flexibility and smoother caused poor binding with cement. The best compressive strength and flexural strength results were obtained with the percentages of coconut fiber as 5% which value as 26.67 N/mm2 and 5.08 N/mm2 respectively.


2011 ◽  
Vol 306-307 ◽  
pp. 814-818 ◽  
Author(s):  
Sheng Hui Song ◽  
Fu Tian Liu

Two kinds of polymer fiber and polymer latex are used to improve the toughness and bondability of cement mortar. The influences of the fiber and latex on the compressive and flexural strength, compressive strength-flexural strength ratio (CS/FS), bond flexural strength and compactedness of the hardened mortar were studied. The results showed that both of the latex and fibre can improve the compressive and flexural strength of mortar in low content, decrease the CS/FS, and then improve the toughness significantly. The bond flexural strength of mortar can be improved by 40-50% when the latex is added. The effect of fibre-latex added together was better than that of two matters added separately. The optimized components for Fibre-Latex hybrid were: 0.28% of PVA+5% of ACE.


2021 ◽  
Vol 13 (8) ◽  
pp. 4546
Author(s):  
Kaiyue Zhao ◽  
Peng Zhang ◽  
Bing Wang ◽  
Yupeng Tian ◽  
Shanbin Xue ◽  
...  

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1707 ◽  
Author(s):  
Yu-You Wu ◽  
Longxin Que ◽  
Zhaoyang Cui ◽  
Paul Lambert

Concrete made from ordinary Portland cement is one of the most widely used construction materials due to its excellent compressive strength. However, concrete lacks ductility resulting in low tensile strength and flexural strength, and poor resistance to crack formation. Studies have demonstrated that the addition of graphene oxide (GO) nanosheet can effectively enhance the compressive and flexural properties of ordinary Portland cement paste, confirming GO nanosheet as an excellent candidate for using as nano-reinforcement in cement-based composites. To date, the majority of studies have focused on cement pastes and mortars. Only limited investigations into concretes incorporating GO nanosheets have been reported. This paper presents an experimental investigation on the slump and physical properties of concrete reinforced with GO nanosheets at additions from 0.00% to 0.08% by weight of cement and a water–cement ratio of 0.5. The study demonstrates that the addition of GO nanosheets improves the compressive strength, flexural strength, and split tensile strength of concrete, whereas the slump of concrete decreases with increasing GO nanosheet content. The results also demonstrate that 0.03% by weight of cement is the optimum value of GO nanosheet dosage for improving the split tensile strength of concrete.


2019 ◽  
Vol 262 ◽  
pp. 06002 ◽  
Author(s):  
Magdalena Dobiszewska ◽  
Waldemar Pichór ◽  
Paulina Szołdra

The study evaluates the use of waste basalt powder as a replacement of cement to enhance hydration of cement and mortar properties. The basalt powder is a waste resulting from preparation of aggregate used in asphalt mixture production. Previous studies have shown that analysed waste used as a fine aggregate replacement has a beneficial effect on some properties of mortar and concrete, i.e. compressive strength, flexural strength and freeze resistance. The present study shows the results of the research concerning the modification of cement paste and mortar with basalt powder. The modification consists in adding the powder waste as a partial replacement of cement. The percentages of basalt powder in this research are 0-40% and 0-20% by mass of cement in the pastes and mortars respectively. The experiments were carried out to determine the influence of basalt powder on cement hydration, as well as compressive and flexural strength. Results indicate that addition of basalt powder as a replacement of cement leads to deterioration of compressive strength. The flexural strength of mortar is improved in some cases. Waste basalt powder only slightly influences the cement hydration.


2011 ◽  
Vol 228-229 ◽  
pp. 627-633
Author(s):  
Tammam Merhej ◽  
Liang Liang Cheng ◽  
De Cheng Feng

The effect of adding polypropylene fibers; with different shapes and volume fractions; on the compressive strength, modulus of rupture, load-deflection curve and flexural toughness (equivalent flexural strength ratio) of concrete was investigated. Crimped and twisted polypropylene fibers were used with 0.0%, 0.2%, 0.4% and 0.6% volume fractions. It was found that the compressive strength, flexural strength and the equivalent flexural strength ratio of concrete increased about 11%, 25% and 40% respectively by adding 0.6% volume fraction of twisted polypropylene fiber. In addition; it was found that the contribution of polypropylene fiber to the flexural strength and flexural toughness was more effective when twisted polypropylene fiber was added comparing to crimped polypropylene fibers. The experimental results were used in numerical example using FAARFIELD program to explore the airfield pavement thickness reduction resulted from polypropylene fiber incorporation.


2013 ◽  
Vol 539 ◽  
pp. 230-234 ◽  
Author(s):  
Bao Min Wang ◽  
Yuan Zhang ◽  
Ming Li

The optimum burning temperature of kaolinite and the optimum proportion of metakaolin (MK) in cement paste were studied by the compressive strength ratio method. Metakaolin was obtained at different burning temperature of 700°C, 750°C, 800°C and 850°C for 4 hours, and mixed into cement with the incorporation of 0, 5wt.%, 10wt.%, 15wt.% and 20wt.%. At last, the mechanical properties were researched. The influence of different burning temperature on hydration products of metakaolin cement mortar were analyzed. The results show that the compressive strength ratio of metakaolin cement mortar and the metakaolin pozzolanicity reach the maximum when the metakaolin obtained by heat treating of 750°C, the optimum proportion of metakaolin in cement is 10%~15%.


2011 ◽  
Vol 396-398 ◽  
pp. 380-385
Author(s):  
Lei Wang ◽  
Ye Wang ◽  
Tian Hua Yang ◽  
Run Dong Li

Large amount of emissions from industrial waste residue to the environment has caused serious pollutions. Utilization way to using industrial waste residue preparing sulfoaluminate cement (SAC) is got much attention of scholars both at home and abroad. It summarized the present researches for preparation of SAC from industrial waste residue (IWR). Sintering temperature, mineral composition, physical properties (fineness, standard viscosity, setting time), mechanical properties (compressive strength, flexural strength) and corrosion resistance of cement clinker were analyzed. Preparation of SAC clinker using IWR is a very promising environmental technology.


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