Effect of Air-entrained Agent for the Mortar of Roller Compacted Concrete

2021 ◽  
Vol 2 (1) ◽  
pp. 26-34
Author(s):  
Tek Raj Gyawali
Keyword(s):  
Compressive Strength ◽  
Freezing And Thawing ◽  
Conventional Concrete ◽  
Roller Compacted Concrete ◽  
Air Content ◽  
Key Factor ◽  
Materials Used ◽  
Entrapped Air ◽  
Strength And Durability ◽  
Air Cells

Roller compacted concrete (RCC) is the zero slump concrete produced from the same materials used in conventional concrete. The mortar used in RCC plays a significant role for the workability, strength and durability of the concrete. The air content in the mortar is the key factor for durability, especially to resist the freezing and thawing action. The main target is to produce the microscopic air cells inside the mortar using air-entrained agent and minimize the entrapped air as little as possible. Air content may range from 4~7% depending upon the type of concrete. The effect of the content of AE 303A type air-entrained agent was studied for the fresh and hardened properties of the RCC mortar. The result showed that it has an almost negligible effect on the workability of mortar, but highly effective for the density and compressive strength of hardened mortar. The use of 0.02% (by weight of cement) increased the air content about 4.5 times of the base mortar (without the use of the agent), from 2% to 9.1%. However, the density was decreased by about 10 % (from 2.18 gm/cm3 to 1.96 gm/cm3) and the 28 days compressive strength by about 49% (from 21.90 MPa to 14.73 MPa). The model, developed for the mortar of the dam concrete, has also been well satisfied with the experimental results for the case of RCC mortar.

scholarly journals Strength, sustainability and affordability of bamboo and mud bricks as materials used in local construction

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Leopold Mbereyaho ◽  
Jean de Dieu Mutabaruka ◽  
Abaho G. Gershome ◽  
Armel Ineza ◽  
Ezra Ngirabatware
Keyword(s):  
Compressive Strength ◽  
Cost Estimation ◽  
Building Materials ◽  
Construction Materials ◽  
Conventional Concrete ◽  
Environment Friendly ◽  
Study Results ◽  
Mud Bricks ◽  
Materials Used ◽  
Sisal Fibers

The construction industry is one of the rapidly growing and the cost analysis suggests that the materials cost is constantly increasing. The continuous extraction of aggregates intensively used in the field is negatively acting to the environment. Therefore research in construction materials should focus not only on discovering new alternative materials but also in appreciating the quality of those locally available for their better application. This research aimed at evaluating the performance of bamboo and mud bricks as two available local building materials, especially with regards not only to their strength but also to new performance concepts which are affordability, energy efficiency and environment friendly aspects. The study comprised mainly of laboratory tests of used materials and cost estimation analysis. Study results established that the considered bamboo and mud bricks, made in ordinary soils and reinforced by sisal fibers were reusable, environment friendly materials and energy efficient, with the bamboo showing the thermal conductivity equal to 0.1496 W/mK. Regarding the compressive strength, reinforced mud bricks with sisal fibers showed an increased value from 1.75 MPA to 4.29MPA, what was in line with related previous studies. The average compressive strength of the studied Arundinaria Alpine bamboo was established at 133,7MPA, while its tensile strength was 88.16MPA and these values were reasonable with comparison to other conventional materials. It is recommended that further research in checking the performance of other types of bamboo as well as about new construction technologies be undertaken in order to enhance the service life of both bamboo and mud bricks.Keywords: Affordability, Bamboo, Conventional concrete, Materials strength, Mud reinforced bricks, Sustainability

scholarly journals Examining the Impact of Micro Silica Gel Additive on the Compressive Strength and Water Absorption of Roller Compacted Concrete Pavement

2016 ◽  
Vol 10 (5) ◽  
pp. 194
Author(s):  
Rouholla Barati ◽  
Seyed Ali Sahaf ◽  
Mehdi Jamshidi ◽  
Alireza Razazpor
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Silica Gel ◽  
Concrete Pavement ◽  
Mix Design ◽  
Concrete Pavements ◽  
Roller Compacted Concrete ◽  
Strength And Durability ◽  
Micro Silica ◽  
The Impact

<p>Roller compacted concrete pavement (RCCP) is one of the different types of concrete pavements which is considered as a new developing technology due to its rapid installation. However, RCCP is difficult to install in high thickness; therefore, it is essential to reduce the thickness of pavement while maintaining strength. Flexural strength and fatigue resistance are the most important parameters effective on design of thick pavements. These parameters are directly related to uniaxial compressive strength of concrete. Hence, this study determines and evaluates the compressive strength of 7-day and 28-day specimens. Given the durability of concrete pavements, particularly their penetrability against water, corrosive materials and minerals, the most important parameter is to reduce water absorption of RCCP. In order to increase strength and reduce water absorption of RCCP, different additives as well as a proper mix design can be significantly effective. This study examines the effect of various mix designs and different percentages of micro silica gel on RCCP. The suggested mix design is continuous aggregation and addition of 7% micro silica gel, which increases strength and durability of RCCP.</p>

scholarly journals Feasibility Tests on Concrete with Very-High-Volume Supplementary Cementitious Materials

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Keun-Hyeok Yang ◽  
Yong-Su Jeon
Keyword(s):  
Compressive Strength ◽  
Weight Ratio ◽  
High Volume ◽  
Cementitious Materials ◽  
Positive Influence ◽  
Supplementary Cementitious Materials ◽  
Early Age ◽  
Freezing And Thawing ◽  
Strength And Durability ◽  
Very High

The objective of this study is to examine the compressive strength and durability of very high-volume SCM concrete. The prepared 36 concrete specimens were classified into two groups according to their designed 28-day compressive strength. For the high-volume SCM, the FA level was fixed at a weight ratio of 0.4 and the GGBS level varied between the weight ratio of 0.3 and 0.5, which resulted in 70–90% replacement of OPC. To enhance the compressive strength of very high-volume SCM concrete at an early age, the unit water content was controlled to be less than 150 kg/m3, and a specially modified polycarboxylate-based water-reducing agent was added. Test results showed that as SCM ratio (RSCM) increased, the strength gain ratio at an early age relative to the 28-day strength tended to decrease, whereas that at a long-term age increased up toRSCMof 0.8, beyond which it decreased. In addition, the beneficial effect of SCMs on the freezing-and-thawing and chloride resistances of the concrete decreased atRSCMof 0.9. Hence, it is recommended thatRSCMneeds to be restricted to less than 0.8–0.85 in order to obtain a consistent positive influence on the compressive strength and durability of SCM concrete.

scholarly journals Performance of Modified Rubber Aggregate Concrete with GGBS and Silica

2019 ◽  
Vol 9 (2) ◽  
pp. 2438-2441
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Research Programme ◽  
Conventional Concrete ◽  
Aggregate Concrete ◽  
Waste Rubber ◽  
Strength And Durability ◽  
Micro Silica

Transfer of tyre rubber suit a tremendous difficulty in India step by step. Analysts are attempting to utilize waste rubber in structural building venture from numerous days back. When coarse aggregate was replaced with 20% chipped rubber it was found that the optimum replacement is5% but still there is a deficit in some strength from conventional concrete. This research programme tries to minimise this gap by adding extra 5% micro silica of the weight of cement and also by replacing 40% of cement by GGBS. Here cubes, cylinders, and prisms were casted to test compressive strength, tensile strength, flexural strength, and durability against heat and were observed after 28 days and 56 days

Seashells and Oyster Shells: Biobased Fine Aggregates in Concrete Mixtures

2022 ◽  
Author(s):  
Giuliana Scuderi
Keyword(s):  
Compressive Strength ◽  
Relevant Literature ◽  
Primary Component ◽  
Natural Sand ◽  
Conventional Concrete ◽  
Air Content ◽  
Concrete Mixtures ◽  
Fine Aggregates ◽  
Alternative Materials ◽  
Mixing Water

The construction industry is the largest global consumer of materials, among which sand plays a fundamental role; now the second most used natural resource behind water, sand is the primary component in concrete. However, natural sand production is a slow process and sand is now consumed at a faster pace than it’s replenished. One way to reduce consumption of sand is to use alternative materials in the concrete industry. This paper reports the exploratory study on the suitability of aquaculture byproducts as fine aggregates in concrete mixtures. Seashell grit, seashell flour and oyster flour were used as sand replacements in concrete mixtures (10%, 30% and 50% substitution rates). All the mixtures were characterized in fresh and hardened states (workability, air content, compressive strength and water absorption). Based on compressive strength, measured at 7 and 28 days, seashell grit provided the most promising results: the compressive strength was found to be larger than for conventional concrete. Moreover, the compressive strength of the cubes was larger, when larger percentages of seashell grit were used, with the highest value obtained for 50% substitution. However, for oyster flour and seashell flour, only 10% sand substitution provided results comparable with the control mixture. For the three aggregates, workability of concrete decreases with fineness modulus decrease. For mixtures in which shell and oyster flour were used with 30% and 50% substitution percentages, it was necessary to increase the quantity of mixing water to allow a minimal workability. In conclusion, considering the promising results of the seashell grit, it is suggested to study further the characteristic of the material, also considering its environmental and physical properties, including acoustic and thermal performances. Higher substitution percentages should also be investigated. This research adds to the relevant literature in matter of biobased concrete, aiming at finding new biobased sustainable alternatives in the concrete industry.

scholarly journals Effects of Incorporation of Marble Powder Obtained by Recycling Waste Sludge and Limestone Powder on Rheology, Compressive Strength, and Durability of Self-Compacting Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Rayed Alyousef ◽  
Omrane Benjeddou ◽  
Chokri Soussi ◽  
Mohamed Amine Khadimallah ◽  
Abdeliazim Mustafa Mohamed
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Limestone Powder ◽  
Self Compacting Concrete ◽  
Limestone Filler ◽  
Air Content ◽  
Marble Powder ◽  
Strength And Durability

Marble has been commonly used as a building material since ancient times. The disposal of waste materials from the marble industry, consisting of sludge that is composed of powder mixed with water, is one of the current worldwide environmental problems. This experimental study aims to valorize marble powder, which is achieved by grinding the sludge as filler added to the cementitious matrix of self-compacting concrete (SCC). The main purpose of this work is to evaluate the marble filler effects on the rheology in the fresh state and on the hardened properties of SCCs compared to those of limestone filler. To this end, two SCCs, SCCM and SCCL, manufactured using marble powder and limestone filler, respectively, were prepared and tested. The fresh properties of the two SCCs’ mixtures were determined by slump flow, L-box, V-funnel, sieve stability, bulk density, and air content. Tests on hardened SCCs included compressive strength, homogeneity, and quality in terms of ultrasonic pulse velocity and durability against carbonation and water penetration. In addition, scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to analyze the specimens.

scholarly journals Estudio de la resistencia a compresión del hormigón utilizando el vidrio finamente molido en reemplazo parcial del cemento

2020 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Sophía Moncerrat Alvarado Mera ◽  
Andy Gabriel Vélez Soledispa ◽  
Wilter Enrique Ruiz Párraga ◽  
Eduardo Humberto Ortiz Hernández ◽  
César Mauricio Jarre Castro
Keyword(s):  
Compressive Strength ◽  
Raw Materials ◽  
Construction Material ◽  
Sustainable Construction ◽  
Ground Glass ◽  
Partial Replacement ◽  
Conventional Concrete ◽  
Renewable Raw Materials ◽  
Test Pieces ◽  
Strength And Durability

  El hormigón obtenido a partir de vidrio finamente molido es una línea de investigación a nuevos materiales, basados en el ahorro del cemento y a su vez en la disminución del dióxido de carbono a la atmósfera para obtener un material constructivo más eficiente y sostenible. Con el propósito de buscar una solución para la fabricación de hormigones, la utilización del vidrio finamente molido como reemplazo parcial del cemento es una de las alternativas para integrarlo al proceso constructivo, cuyo objetivo es disminuir el empleo de materias primas no renovables, utilizando materiales reciclados con excelentes características de resistencia y durabilidad. En la presente investigación se estudió la resistencia a compresión del hormigón, usando vidrio finamente molido, sustituyéndolo en porcentajes del 5%, 10% y 15% en reemplazo parcial del cemento. Se elaboraron probetas de hormigón convencional y probetas de hormigón con adición de vidrio finamente molido, a cada probeta experimentada se le realizó el ensayo de resistencia a compresión del hormigón en un tiempo máximo de curado húmedo de 56 días. Se realizó la comparación entre el hormigón sin adición y el hormigón con porcentajes de vidrio finamente molido, llegando a la conclusión que el vidrio sustituido al 15% como reemplazo parcial del cemento disminuye su resistencia a compresión.   Palabras claves — vidrio finamente molido, resistencia a compresión, hormigón, adición, cemento.   Abstract  The concrete obtained from finely ground glass is a line of investigation to new materials, based on the saving of cement and in turn on the reduction of carbon dioxide to the atmosphere to obtain a more efficient and sustainable construction material. In order to find a solution for the manufacture of concrete, the use of finely ground glass as a partial replacement of cement is one of the alternatives to integrate it into the construction process, whose aim is to reduce the use of non-renewable raw materials, using recycled materials with excellent strength and durability characteristics. In this research, the compressive strength of concrete was studied, using finely ground glass, replacing it in percentages of 5%, 10% and 15% in partial replacement of cement. Conventional concrete test pieces and concrete test pieces with the addition of finely ground glass were produced and each tested test piece was tested for the compressive strength of the concrete within a maximum curing time of 56 days A comparison was made between aggregate concrete and concrete with finely ground glass percentages, concluding that glass replaced at 15% as a partial replacement for cement decreases its compressive strength.   Index Terms — finely ground glass, compressive strength, concrete, addition, cement.

scholarly journals Effect on Addition of Nano "Titanium Dioxide” (TiO2)on Compressive Strength of Cementitious Concrete

10.29007/sq9d ◽  
2018 ◽  
Author(s):  
Jay Sorathiya ◽  
Siddharth Shah ◽  
Smit Kacha
Keyword(s):  
Compressive Strength ◽  
Titanium Dioxide ◽  
High Performance ◽  
Nano Materials ◽  
Cementitious Composite ◽  
Strength Parameters ◽  
Conventional Concrete ◽  
High Compressive Strength ◽  
Strength And Durability ◽  
Nano Titanium Dioxide

Cementitious concrete has great practical difficulties in achieving high compressive strength and durability of high performance structures. But it becomes a challenge to increase the compressive strength and durability of particular cementitious composite and also maintaining basic desirable properties of concrete. This paper addresses these problems by the addition of nano-materials. In this study, an attempt is made to understand the effect of Anatase Nano Titanium Dioxide (TiO2), on Conventional Concrete (CC) of M20 grade with various proportions 0.5%, 0.75%, 1.0%, 1.25%, 1.5% in relation with the weight of cement. The Workability, Strength parameters at various proportions of Anatase Nano Titanium Dioxide (TiO2) are tested at different durations. The results obtained are being discussed in the paper.

scholarly journals Deltaic Lateritic Soil in 1:5:11 Mix Design for Producing Controlled Low-Strength Material (CLSM) for Pavement Backfill

2021 ◽  
Vol 18 (3) ◽  
pp. 244-250
Author(s):  
J.A. Oke
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Mix Design ◽  
Lateritic Soil ◽  
Strength Development ◽  
Conventional Concrete ◽  
Strength Material ◽  
Low Strength ◽  
Controlled Low Strength Material ◽  
Materials Used

Deltaic lateritic soil obtained from Emohua in Rivers State, Nigeria was studied to ascertain its suitability as a substitute to sand in concrete for producing controlled low-strength material (CLSM). Cement, coarse aggregate, as well as lateritic soil which replaced sand was combined in ratio 1:5:11 to produce lateritic concrete using varying water-cement (w/c) ratios at varying curing durations. Variation in the w/c ratios ranging from 0.2 to 0.5 at 0.1 intervals and the curing periods which varied between 7, 14 and 28 days were examined. As with the case with conventional concrete, strength development, as well as cement hydration took place after casting over the curing periods. Recent applications using CLSM recommends that a compressive strength of 8.3 N/mm2 or less is required for materials used as conventional compacted backfill soil or structural fillings. In a situation where future excavation is envisioned, it is recommended that the maximum long-term compressive strength of CLSM should generally have an upper limit of 2.1 N/mm2 for compacted backfill material hence, the lateritic concrete produced in this study using the 1:5:11 mix design at 0.2 w/c ratio, cured for 28 days which gave strength of 5.3 N/mm2 can be used as CLSM which primarily, can be utilized as a substitute for compacted backfill to sub-base and/or subgrade of flexible pavements. Where necessary, super plasticizer can be introduced to increase flowability of the lateritic concrete.

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