scholarly journals The Effect of Various Polynaphthalene Sulfonate Based Superplasticizers on the Workability of Reactive Powder Concrete

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Anthony Torres ◽  
Federico Aguayo ◽  
Srinivas Allena ◽  
Michael Ellis

A superplasticizer is a type of chemical admixture used to alter the workability (viscosity) of fresh concrete. The workability of fresh concrete is often of particular importance when the water-to-cement (w/c) ratio is low and a particular workability is desired. Reactive Powder Concrete (RPC) is a high-strength concrete formulated to provide compressive strengths exceeding 130MPa and made of primarily powders. RPC materials typically have a very low w/c, which requires the use of a chemical admixture in order to make the material workable for placing, handling and consolidating. Superplasticizer are commonly used for this purpose. Superplasticizers are developed from different formulations, the most common being Polynaphthalene Sulfonate (PNS), Polymelamine Sulfonate (PMS) and Polycarboxylate Ether (PCE). This study investigates the impact of various PNS based superplasticizers on the compressive strength and rheological performance of a RPC mixture. Six different types of PNS based superplasticizers were used; three of various compositional strengths (high, medium, low range) from a local provider, and three of the same compositional strengths (high, medium, low) from a leading manufacturer. Specific properties assessed were the superplasticizers viscosity, concrete workability through the mortar-spread test, concrete rheology, and 7, 14, and 28 day RPC compressive strengths. Two mixtures were produced with two w/cm (0.20 and 0.15), which would subsequently increase the amount of superplasticizer needed, from 34.7L/m3 to 44.5L/m3. The results show that the name brand high range composition produced the overall highest spread, lowest viscosity, and a highest compressive strength at all ages tested. However, the local provider outperformed the name brand in the mid and low range compositions. Additionally, the rheology test also demonstrated that the name brand high range, and RPC produced with the name brand high range, had a lower viscosity at all angular speeds than the others tested.

2019 ◽  
Vol 11 (2) ◽  
pp. 95-100
Author(s):  
Anthony Torres ◽  
Federico Aguayo ◽  
Srinivas Allena ◽  
Michael Ellis

Ultra-High Strength Concrete (UHSC) is a high-strength and highly ductile material formulated to provide compressive strengths exceeding 130MPa. UHSC materials typically have a very low water-to-cementitious ratio (w/cm), which requires the use of superplasticizers to disperse the fine particles and to make the material workable for placing, handling and consolidating. Common examples of superplasticizer compositions include Polynaphthalene Sulfonate (PNS), Polymelamine Sulfonate (PMS) and Polycarboxylate Ether (PCE) based polymers. This study focuses on assessing the impact of various superplasticizers on the compressive strength and rheological performance of a UHSC mixture. Four different types of superplasticizers were used; two different PCE based superplasticizers from a leading manufacturer, one PNS superplasticizer, and one PCE superplasticizer, both of which were provided by a local chemical provider. Specific properties assessed were the superplasticizers’ viscosity, concrete workability through the mortar-spread test, concrete rheology, and 7, 14, and 28 day compressive strengths. Two mixtures were produced with two w/cm (0.20 and 0.15), which would subsequently increase the amount of HRWRA needed, from 34.7L/m3 to 44.5L/m3. The results show that both name brand PCE superplasticizers produce a higher spread, lower viscosity, and a higher compressive strength at all ages tested up to 28 days than the two local superplasticizers. Additionally, the rheology test demonstrated that the name brand PCE superplasticizers, and UHSC produced with such superplasticizers, had a lower viscosity at all angular speeds than the local superplasticizers counterparts.


2010 ◽  
Vol 150-151 ◽  
pp. 779-782
Author(s):  
Qing Xin Zhao ◽  
Zhao Yang Liu ◽  
Jin Rui Zhang ◽  
Ran Ran Zhao

By means of the three-point bending impact equipment, with the measurement of ultrasonic velocity, the impact behavior and damage evolution of reactive powder concrete (RPC) with 0, 1%, 2% and 3% volume fraction of steel fiber were tested. The results showed that steel fiber significantly improved the compressive strength, flexural strength, flexural toughness and impact toughness of RPC matrix. The compressive strength, flexural strength, flexural toughness of RPC with 3% steel fiber increased by 40.1%, 102.1%, and 37.4 times than that of plain concrete, respectively, and simultaneously, the impact toughness of RPC with 3% steel fiber was 93.2 times higher than that with 1% steel fiber. RPC with 2% and 3% steel fiber dosage both had relatively high compressive strength, flexural strength and flexural toughness; however, compared with the sample with 2% steel fiber dosage, the impact toughness of RPC with 3% steel fiber dosage increased by more than 10 times. Therefore, taking economy and applicability into consideration, if we mainly emphasis on the compressive strength, flexural strength and flexural toughness, RPC with 2% steel fiber is optimal. While if impact toughness is critical, RPC with 3% steel fiber would be the best choice.


2019 ◽  
Vol 4 (6) ◽  
pp. 74-83 ◽  
Author(s):  
Gamal I. K. ◽  
K. M. Elsayed ◽  
Mohamed Hussein Makhlouf ◽  
M. Alaa

Reactive Powder Concrete RPC is comprise of (cement, quartz powder, sand, and superplasticizer) mixture with low water/cement ratio. It has not coarse aggregates and characterized by highly dense matrix, high strength concrete, excellent durability, and economic. This study aims to investigate fresh and hardened properties of locally cast RPC with several available economical materials such as silica fume (SF), fly ash (FA), steel fiber (STF), and glass fiber (GF). Experimental investigation were performed to study the effectiveness of partial replacement of cement by SF or FA to reach ultra-high strength concrete, effect of additional materials STF or GF in order to improve the fracture properties of the RPC mixes, and influence of the treated with normal water as well as with hot water. Fifteen different RPC mixes were cast with 20, 25, 30, and 35% cement replacement by SF, 25% cement replacement by FA, and another proportions taken combination between SF and FA with percentages 15, 20, 25% FA and constant 10% SF. Varying fiber types (steel fiber or glass fiber) added to concrete by different percentages 1, 2, and 3%. Specimens were treated with normal water 25ᵒC and hot water at 60ᵒC and 90ᵒC by 2 mixes with silica fume content 25% of binder and steel fiber content 2% by total volume. Performance of the various mixes is tested by the slump flow, compressive strength, flexure strength, splitting tensile strength, and density. The production of RPC using local materials is successfully get compressive strength of 121 MPa at the age of 28 days at standard conditions and normal water curing 25°C with Silica fume content 25% of binder and steel fiber content 2% by total volume of RPC and water/binder ratio of 0.25.  The results also showed the effect of curing by hot water 60 and 90°C, it is observed that compressive strength increases proportionally with curing temperatures and a compressive strength of 149.1 MPa at 90°C for 1days was obtained.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1751 ◽  
Author(s):  
Guangyao Yang ◽  
Jiangxiong Wei ◽  
Qijun Yu ◽  
Haoliang Huang ◽  
Fangxian Li

This study investigated the strength and toughness of reactive powder concrete (RPC) made with various steel fiber lengths and concrete strengths. The results indicated that among RPC samples with strength of 150 MPa, RPC reinforced with long steel fibers had the highest compressive strength, peak strength, and toughness. Among the RPC samples with strength of 270 MPa, RPC reinforced with short steel fibers had the highest compressive strength, and peak strength, while RPC reinforced with medium-length steel fibers had the highest toughness. As a result of the higher bond adhesion between fibers and ultra-high-strength RPC matrix, long steel fibers were more effective for the reinforcement of RPC with strength of 150 MPa, while short steel fibers were more effective for the reinforcement of RPC with strength of 270 MPa.


2020 ◽  
Vol 857 ◽  
pp. 15-21
Author(s):  
Nesreen B. Najib ◽  
Shatha D. Mohammed ◽  
Wasan Z. Majeed ◽  
Nada Mahdi Fawzi A. Jalawi

Reactive Powder Concrete (RPC) could be considered as the furthermost significant modern high compressive strength concrete. In this study, an experimental investigation on the impact of micro steel fiber volume fraction ratio and gamma ray irradiation duration influence upon the compressive strength of RPC is presented. Three volume fraction ratios (0.0, 1.0 and 1.5) % was implemented. For each percentage of the adopted fiber ratios, six different irradiation duration was considered; these are (1, 2, 3, 4, 5 and 6) days. Gamma source (Cs-137) of energy (0.662) MeV and activity (6) mci was used. In a case of zero volume fraction ratio, the experimental results showed that gamma ray had a significant influence on the reducing of the compressive strength varies between (1.2-8.6)% for a period of (1-6) days, respectively. Although there was a decrease in the compressive strength for a state of non-zero volume fraction ratio (1 and 1.5) % varies between (1.0-3.1 and 0.4-1.6) %, respectively, the attained results indicated that gamma ray had no significant effect to reduce the compressive strength of the RPC that’s included micro steel fibers as a volume fraction.


Author(s):  
Qifeng Zhu ◽  
Zhengxiang Huang ◽  
Qiangqiang Xiao ◽  
Xudong Zu ◽  
Xin Jia

In this study, a semi-empirical model was proposed to calculate the penetration depth and cavity diameters generated by shaped charge jet into high and ultra-high strength concrete (H&UHSC) targets. A recently proposed axial penetration equation and the two-step mechanism of cavity growth were employed to determine the analysis. The predictions were validated with reference to the experiments conducted using a kind of H&UHSC named reactive powder concrete (RPC). Furthermore, the influences of the RPC compressive strength and the jet velocity on the penetration were analyzed. The results showed that the RPC targets had good protection efficiency for both penetration depth and cavity diameters as the compressive strength approaches approximately 250∼280MPa. Moreover, the radial cavity growth efficiency increased linearly with the increase of the jet velocity, while the axial penetration efficiency increased rapidly when the jet velocity was 1.0∼4.0km/s and reached the maximum at 4.0∼7.0km/s and tended to be stable as the jet velocity increased to greater than about 7.0km/s.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 552
Author(s):  
Jeganmurugan P ◽  
Rakesh Senthil Kumar G V ◽  
Sivasharmina M ◽  
Sowmiya S ◽  
Vasanthan M

Reactive powder concrete (RPC) is ultra high strength with advanced mechanical properties. Reactive powder concrete is a concrete without coarse aggregate, contains cement, silica fume, quartz sand, quartz powder, super plasticizer, steel fibre and polypropylene fibre with very low water cement ratio under normal curing condition. RPC has been produce with high compressive strength ranging from upto 800 MPa with high flexural strength up to 50 MPa and in some cases provided with absences of steel reinforcement. Mix proportions of RPC were found by trial and error method, the concrete cubes of size 100mmx100mmx100mm were cast for find compressive strength of NRPC at 7days. Concrete cubes and cylinders of sizes 100mmx100mmx100mm and 100mmx150mm have to be cast for finding compressive strength and split tensile strength at 28 days. Flexural strength of NRPC and MRPC will be find out by casting prism of size 500mmx 100mmx 100 mm. The optimum mix proportion has to be finalized by comparing the results of all concrete specimens. Compressive strength test results shows that addition of silica fume upto 0.22% will increase the compressive strength of reactive powder concrete.   


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eethar Thanon Dawood

Superplasticizer is one of the most common types of chemical admixtures used in the mortar or concrete, especially that characterized high performance like Reactive powder concrete. Recently, the chemical admixture is considered as one of the main components of cement-based products due to it has a significant role to improve the physical and mechanical properties generally. Therefore, the experimental work of this research has been an attempt to study the influence of two types of superplasticizers with different dosages on the properties of reactive powder concrete. The workability, compressive strength, and saturated surface dry density of reactive powder concrete used two types of chemical admixture(superplasticizer) individual and in combination have been studied and compared together. The results indicated that the use of superplasticizer type ViscoCrete-5930 in individual or combination with superplasticizer type KUT PLAST PCE600 has a positive impact on the properties of reactive powder concrete especially its flowability and compressive strength. Keywords:Reactive powder concrete; Superplasticizer; Flowability; Compressive strength; Saturated surface dry density;


2018 ◽  
Vol 7 (4) ◽  
pp. 2753
Author(s):  
Ibtihal Fadhil ◽  
Ayad K. Kadhem ◽  
Nisreen Salih

Reactive powder concrete is a new concrete that has been used in recent years because of many advantages. The use of reactive powder concrete in structural elements such as beams provides higher compressive strength, higher modulus of elasticity, durable concrete and increasing the concrete ductility, so that the concrete has high resistance against tensile stress. The experimental tests of the reinforced concrete beams under the effects of impact loadings are investigated in this paper. The parameters being adopted in present paper are steel fiber of (1, 1.5 and 2%) by volume, dropped mass and height of drop. The reinforced concrete specimens were tested under impact load by one strike only. The test results indicate that the impact force increased when the compressive strength of concrete increased that when the steel fiber ratio becomes more and the deflection has become less.  


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2948 ◽  
Author(s):  
Stefania Grzeszczyk ◽  
Aneta Matuszek-Chmurowska ◽  
Eva Vejmelková ◽  
Robert Černý

The paper presents the test results of basalt fiber impact on a compressive and flexural strength, resistance to abrasion and porosity of Reactive Powder Concrete (RPC). The reasons for testing were interesting mechanical properties of basalt fibers, the significant tensile strength and flexural strength, and in particular the resistance to high temperatures, as well as a relatively small number of RPC tests performed with those fibers and different opinions regarding the impact of those fibers on concrete strength. The composition of the concrete mix was optimized to obtain the highest packing density of particles in the composite, based on the optimum particle size distribution curve acc. to Funk. Admixture of basalt fibers was used in quantity 2, 3, 6, 8 and 10 kg/m3, length 12 mm and diameter 18 µm. A low water-to-binder ratio, i.e., from 0.24, was obtained through application of a polycarboxylate-based superplasticizer. The introduction of up to 10 kg/m3 of basalt fibers to RPC mix was proved to be possible, while keeping the same w/c ratio equal to 0.24, with a slight loss of workability of the concrete mix as the content of fibers increased. It was found that the increase of the fiber content in RPC to 10 kg/m3, despite the w/c ratio was kept the same, caused reduction of the concrete compressive strength by 18.2%, 7.8% and 13.6%, after 2, 7, and 28 days respectively. Whereas, the flexural strength of RPC increased gradually (maximum by 15.9%), along with the fiber quantity increase up to 6 kg/m3, and then it reduced (maximum by 17.7%), as the fiber content in the concrete was further increased. The reduction of RPC compressive strength, along with the increase in basalt fibers content, leads to the increase of the total porosity, as well as the change in pore volume distribution. The reduction of RPC abrasion resistance was demonstrated along with the increase of basalt fibers content, which was explained by the compressive strength reduction of that concrete. A linear relation between the RPC abrasion resistance and the compressive strength involves a high determination coefficient equal to 0.97.


Sign in / Sign up

Export Citation Format

Share Document