scholarly journals Predicting the drying shrinkage behavior of high strength portland cement mortar under the combined influence of fine aggregate and steel micro fiber

2017 ◽  
Vol 67 (326) ◽  
pp. 119 ◽  
Author(s):  
Zhengqi Li
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Drying Shrinkage ◽  
High Strength ◽  
Fiber Content ◽  
Fine Aggregate ◽  
Aggregate Content ◽  
Normal Strength ◽  
Gardner Model

The workability, 28-day compressive strength and free drying shrinkage of a very high strength (121-142 MPa) steel micro fiber reinforced portland cement mortar were studied under a combined influence of fine aggregate content and fiber content. The test results showed that an increase in the fine aggregate content resulted in decreases in the workability, 28-day compressive strength and drying shrinkage of mortar at a fixed fiber content. An increase in the fiber content resulted in decreases in the workability and drying shrinkage of mortar, but an increase in the 28-day compressive strength of mortar at a fixed fine aggregate content. The modified Gardner model most accurately predicted the drying shrinkage development of the high strength mortars, followed by the Ross model and the ACI 209R-92 model. The Gardner model gave the least accurate prediction for it was developed based on a database of normal strength concrete.

Water Penetration Resistance of Fly Ash Concrete Incorporating with Quarry Wastes

2017 ◽  
Vol 886 ◽  
pp. 159-163 ◽  
Author(s):  
Suppachai Sinthaworn
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Strength ◽  
Cementitious Materials ◽  
Fine Aggregate ◽  
Water Penetration ◽  
Strength Concrete ◽  
Fly Ash Concrete ◽  
Suitable Amount ◽  
Normal Strength

Slump of fresh concrete, compressive strength and water penetration depth under pressure of fly ash concrete incorporate with quarry waste as fine aggregate were investigated. The cementitious materials of the concrete includes ordinary Portland cement 80% and fly ash 20% by weight of cementitious. The mix proportions of the concrete were set into two classes of compressive strength. The results show that fly ash enhances workability of both concretes (normal concrete and concrete incorporate with quarry waste). Increasing the percentage of quarry dusts as fine aggregate in concrete seem negligible effect on the compressive strength whereas adding fly ash shows a slightly improve the compressive strength in the case of cohesive concrete mixture. Besides, adding the suitable amount of fly ash could improve the permeability of concrete. Therefore, fly ash could be a good admixture to improve the water resistant of normal strength concrete and also could be a supplemental material to improve the compressive strength of normal high strength concrete.

Possibility of using recycled waste medical-glass as fine aggregate in normal-strength concrete

2021 ◽  
Vol 15 (3) ◽  
pp. 93-108
Author(s):  
Huynh Thi My Dung ◽  
Huynh Van Hiep ◽  
Huynh Trong Phuoc
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Drying Shrinkage ◽  
Dry Density ◽  
Fine Aggregate ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Normal Strength ◽  
Recycled Waste ◽  
Medical Glass

The possibility of using recycled waste medical-glass aggregate (RGA) as a fine aggregate in the production of normal-strength concrete was investigated in this study. The influence of RGA as crushed sand (CS) replacement at different levels (by volume) of 0 – 100% (an interval of 20%) on the engineering properties and durability of concrete was also studied. Results show that the replacement of CS by RGA insignificantly affected the workability and unit weight of fresh concrete mixtures. Besides, using RGA to replace 20 – 60% CS was beneficial in terms of compressive strength, drying shrinkage, and ultrasonic pulse velocity (UPV). At these replacement levels, the dry density values were found to increase and the water absorption values were reduced as well. However, replacing CS with RGA up to 80% and 100% caused a reduction in compressive strength, dry density, and UPV and an increase in water absorption and drying shrinkage of concretes. Closed correlations among the above-mentioned concrete properties were also found in this study. All of the concrete samples obtained compressive strength values higher than the target strength (≥ 25 MPa) and they were classified as very good quality concretes with UPV values of above 4100 m/s. The experimental results demonstrate a high possibility of producing normal-strength concrete with a fine aggregate of RGA as either partially or fully replacement of CS. This also provides an environmentally-friendly solution for recycling waste medical glass in construction materials for sustainable development.

MECHANICAL PROPERTIES AND SHRINKAGE PROPERTIES OF THE CONCRETE WITH RECYCLED FINE AGGREGATE AND ADMIXTURE

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Yuji Nakata ◽  
Koji Takasu ◽  
Hidehiro Koyamada ◽  
Hiroki Suyama
Keyword(s):  
Compressive Strength ◽  
Pore Volume ◽  
Drying Shrinkage ◽  
High Strength ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Shrinkage Ratio ◽  
Recycled Fine Aggregate ◽  
High Durability ◽  
The Relationship

In Japan, it is forecasted that massive amounts of concrete waste material will be generated in the future as a result of demolition of many buildings, and expansion of the use of recycled aggregate is expected. In this study, it was verified the effect when relatively large amount of admixture is mixed, a combination of recycled fine aggregate of different quality and various admixtures, combination of each admixture in order to realize high strength and high durability by using recycled aggregate. The increase in the drying shrinkage ratio due to the deterioration of the recycled fine aggregate quality was larger than the fluctuation due to the admixture mixing ratio and the drying shrinkage ratio was distributed by forming a group for each quality of recycled fine aggregate. In the relationship between the pore volume and the compressive strength, when evaluated with pore volume of 2 μm or less in both cases, a good linear relationship could be confirmed. The relationship between the pore volume and the drying shrinkage rate was similar. Therefore, it was suggested that compressive strength and drying shrinkage ratio of mortar contained composite recycled fine aggregate and admixture could be predicted by evaluating with the pore volume of 2 μm or less.

scholarly journals An experimental study on production of high strength non-shrink grout containing fly ash

2021 ◽  
Vol 72 (4) ◽  
pp. 477-485
Author(s):  
Chi Dang Thuy
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
High Strength ◽  
Fine Aggregate ◽  
Expansive Agent ◽  
Chemical Admixture ◽  
The University ◽  
The Given

Cement-based grouts are widely used thanks to its outstanding features such as high workability, non-separation, non-bleeding, easy to fulfill small gaps with complex shapes. This paper descrcibes the first phase of a series of laboratory experiments that examined the ability of production of self - levelling mortar at the University of Transport and Communications. The Portland cement-based grout incorporated superplasticizer, fly ash, fine aggregate, water along with expansion agent to match as closed as possible the given high strength non-shrink grout. The experimental study focused on the performance of non-shrink grouts regarding the flowability, expansion and bleeding, strengths and drying shrinkage of the test grout mixtures. The high range water reducer (HRWR) at dosage of 1% by weight of cement was used as a flowability modifying chemical admixture to prevent water segregation and leads to an increase in compressive strength. The parameter tests consist of water-cement ratios, and fixed dosages of superplasticizer and expansive agent. To examine the flowability of grout mortars, the flow cone test was applied. The flow cone test result indicated that there were three proportional of grouts that can meet the requirement of fluidity. The compressive strength of specimens was tested according to ASTM C349-14. It was concluded that the compositions of grouts at a water-cement ratio of from 0.29 to 0.33 have compressive strengths greater than 60 MPa. The tested specimens using the expansive agent with the dosage recommended by the manufacturer meet the non-shrinkage requirement of a grout. The experimental results have demonstrated the ability of production of high strength non-shrink grouts.

Superplasticizer for High Strength Concrete

2015 ◽  
Vol 1768 ◽  
Author(s):  
Luis E. Rendon Diaz Miron ◽  
Maria E. Lara Magaña
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
High Strength Concrete ◽  
High Strength ◽  
Mineral Admixtures ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Normal Strength ◽  
Ready Mixed Concrete ◽  
Mixed Concrete

ABSTRACTIn the early 1970s, experts predicted that the practical limit of ready-mixed concrete would be unlikely to exceed a compressive strength greater than 90 MPa [1]. Over the past two decades, the development of high-strength concrete has enabled builders to easily meet and surpass this estimate. The primary difference between high-strength concrete and normal-strength concrete relates to the compressive strength that refers to the maximum resistance of a concrete sample to applied pressure. Although there is no precise point of separation between high-strength concrete and normal-strength concrete, the American Concrete Institute defines high-strength concrete as concrete with a compressive strength greater than 45 MPa. Manufacture of high-strength concrete involves making optimal use of the basic ingredients that constitute normal-strength concrete. When selecting aggregates to obtain high-strength concrete, we consider strength, optimum size distribution, surface characteristics and a good bonding with the cement paste that affect compressive strength. Selecting a high-quality Portland cement and optimizing the combination of materials by varying the proportions of cement, water, aggregates, and admixtures is also necessary. Any of these properties could limit the ultimate strength of high-strength concrete. Pozzolans, such as fly ash and silica fume along with silicic acid, are the most commonly used mineral admixtures in high-strength concrete. These materials impart additional strength to the concrete by reacting with Portland cement hydration products to create additional Calcium Silicate Hydrate (CSH) gel, the part of the paste responsible for concrete strength; finally the most important admixture is polycarboxylate ether as super plasticizer. It would be difficult to produce high-strength ready-mixed concrete without using chemical admixtures. In this paper we study the use of high performance concrete (HPC) to obtain very narrow strong pre-fabricated elements for water conducting channels.

scholarly journals The properties of slag-silica fume ternary blended mortar with quarry dust

2020 ◽  
Vol 14 (1) ◽  
pp. 6443-6451 ◽  
Author(s):  
Chow Wee Kang ◽  
Cheah Chee Ban ◽  
Oo Chuan Wei ◽  
Part Wei Ken ◽  
Leow Khang Heng
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Drying Shrinkage ◽  
High Strength ◽  
Total Porosity ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Fine Aggregate ◽  
Granulated Blast Furnace Slag ◽  
Quarry Dust

High carbon emissions of manufactured Portland cement in the concrete industry have incurred several interests in reducing the use of Portland cement by partially replacing it with supplementary cementitious materials. Most of which, are by-products from other manufacturing industries. Hence, the main purpose of this study is to investigate the effects of different combinations of ternary blended mortars incorporating supplementary cementitious materials such as Ground Granulated Blast Furnace Slag (GGBS) and Densified Silica Fume (DSF). In this study, mortars were prepared with 100% quarry dust and GGBS was replaced with DSF at 2% step increments up to 16% at a w/b ratio of 0.24. At the same time OPC content was fixed at 50%. The compressive and flexural strength, drying shrinkage, and porosity of mortars were all tested. The results indicated that the increasing DSF content increases; GGBS reduces the superplasticizer dosage for the desired workability of the mortar. The utilization GGBS and DSF has improved the performances ternary blended mortar incorporating quarry dust as a fine aggregate in terms of mechanical strength, drying shrinkage and total porosity tested. The high strength ternary blended mortar incorporating GGBS and DSF exhibited optimum mechanical and durability performance at the OPC:GGBS:DSF ratio of 50:38:12.

scholarly journals Assessment of the influence of fine aggregates on Portland cement mortar compressive strength

2021 ◽  
pp. 100182
Author(s):  
Alberto Muciño ◽  
Lauro Bucio ◽  
Eligio Orozco ◽  
Sofía Vargas ◽  
Nora A. Pérez
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Fine Aggregates

Estimation of Portland cement mortar compressive strength using microcores. Influence of shape and size

2014 ◽  
Vol 55 ◽  
pp. 359-364 ◽  
Author(s):  
F.J. Alejandre ◽  
V. Flores-Alés ◽  
R. Villegas ◽  
J. García-Heras ◽  
E. Morón
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Shape And Size

scholarly journals Properties of Self-curing High Strength Concrete by using Baby Polymer Diapers

2018 ◽  
Vol 203 ◽  
pp. 06022
Author(s):  
Salmia Beddu ◽  
Daud Mohamad ◽  
Fadzli Mohamed Nazri ◽  
Siti Nabihah Sadon ◽  
Mohamed Galal Elshawesh
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Drying Shrinkage ◽  
High Strength ◽  
Strength Test ◽  
Curing Process ◽  
Compressive Strength Test ◽  
Mechanical And Physical Properties ◽  
Compressive Strength Of Concrete ◽  
Strength And Durability

This study investigates the self-curing concrete using baby polymer diapers as substitute method of curing process in order to improve mechanical and physical properties of concrete. Three different proportion of baby polymer diapers which are 1%, 3% and 5% were mix with concrete. Slump, compressive strength and drying shrinkage test were performed in order to study the workability, strength and durability of the concrete. All concrete were tested for 1, 3, 7, 14, and 28 days for drying shrinkage test. Meanwhile, all concrete were test at 3, 7 and 28 days for compressive strength test. Compressive strength of concrete containing 5% baby polymer diapers show the highest strength at 28 days compared to others percentage. Thus, it indicates that application of baby polymer diaper as self-cure agent can improve the concrete performances.

scholarly journals Study of Proportional Variation of Geopolymer Concrete which Self Compacting Concrete

2019 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Purwanto P. ◽  
Himawan Indarto
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plant ◽  
Portland Cement ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Conventional Concrete ◽  
Basic Characteristics ◽  
Carbon Dioxide Co2 ◽  
Proportional Variation

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.

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