scholarly journals Influence of Pore Structure on Compressive Strength of Cement Mortar

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Haitao Zhao ◽  
Qi Xiao ◽  
Donghui Huang ◽  
Shiping Zhang
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Pore Size ◽  
Cement Mortar ◽  
Natural Sand ◽  
Cement Ratio ◽  
Manufactured Sand ◽  
Mix Proportion ◽  
Mercury Porosimeter ◽  
Threshold Radius

This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure.

Investigation of Pore Structure for Manufactured Sand Mortar

2014 ◽  
Vol 534 ◽  
pp. 39-51
Author(s):  
Zheng Hong Tian ◽  
Jing Wu Bu
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Water Saturation ◽  
Total Porosity ◽  
Threshold Region ◽  
Fine Aggregate ◽  
Test Results ◽  
Natural Sand ◽  
Manufactured Sand ◽  
Threshold Radius

This paper focuses on the pore structure parameters of mortars produced with manufactured sand and natural sand via water saturation and MIP methods. Test results show that, total porosity, as well as compressive strength, of manufactured sand mortar, is higher than that of natural sand mortar at fixed w/c and s/c ratio. Furthermore, considerable volume of large pores present in specimens of manufactured sand at higher w/c ratio rather not at the lower w/c ratio, which caused by the larger binder-aggregate interface. Manufactured fine aggregate in mortar probably accelerate hydrated reaction of cement, which result in the most probable pore size is finer than that of natural sand mortar. It can be concluded that the threshold region becomes flatten and threshold radius increases due to the aggregate volume concentration rises. Finally, a new theoretical model with a double-lognormal distribution function is demonstrated to be reasonable to fit pore size distribution in mortars.

Research of Performance of Low Amount of Cement Manufactured-Sand Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1200-1205
Author(s):  
Chun Hui Yu ◽  
Gu Hua Li ◽  
Jin Liang Gao ◽  
Qun Wei ◽  
Da Zhen Xu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Grain Shape ◽  
Great Influence ◽  
Cementitious Materials ◽  
Natural Sand ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Manufactured Sand

Compared with natural sand, manufactured-sand is of small porosity, poor grain shape and graded, which impacts mixes workability and the properties after hardening. In Concrete, playing the role of retaining moisture water is mainly powder, including cement, powder in the sand and fly ash etc. The amount of powder has a great influence on the properties of concrete, especially on its workability. This paper mainly discusses the influence of amount of cement, cementitious materials, fly ash, water-cement ratio and other factors on the workability, compressive strength and shrinkage of concrete. The experiments show that, in the case of the low amount of cement, workability of the manufactured-sand concrete mixture, compressive strength and shrinkage deformation of test block all meet the actual requirements.

Design of Mix Proportion of Cement Mortar with High-Performance Composite Semi-Flexible Pavement

2013 ◽  
Vol 641-642 ◽  
pp. 342-345 ◽  
Author(s):  
Ya Jun Wang ◽  
Chang Ying Guo ◽  
Yan Feng Tian ◽  
Jian Jun Wang
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Cement Mortar ◽  
Rupture Strength ◽  
Flexible Pavement ◽  
Mixture Ratio ◽  
Cement Ratio ◽  
Mix Proportion ◽  
High Performance Composite ◽  
The Relationship

Nine groups of cement mortar with different mix proportion were designed to measure their fluidity 0h, 0.25h, 0.5h, 0.75h and 1h later, compressive strength and rupture strength of 3d, 7d and 28d were also tested to find out the relationship between compressive strength, rupture strength, water-cement ratio and sand-cement ratio by software Origin. Considered the three factors above, the optimum mixture ratio was determined finally to meet the requirements.

scholarly journals Strength Characteristics of M40 Grade Concrete using Waste PET as Replacement for Sand

2021 ◽  
Vol 18 (3) ◽  
pp. 209-218
Author(s):  
S.O.A. Olawale ◽  
M.A. Kareem ◽  
O.Y. Ojo ◽  
A.U. Adebanjo ◽  
M.O. Thanni
Keyword(s):  
Compressive Strength ◽  
Target Strength ◽  
River Sand ◽  
Split Tensile Strength ◽  
Natural Sand ◽  
Cement Ratio ◽  
Mix Proportion ◽  
Global Trend ◽  
Concrete Production ◽  
Free Environment

The wide variety of industrial and domestic applications of plastic products has fuelled a global trend in their use. The vast amount of plastic items that are discarded after use, on the other hand, pollutes the environment. In light of this, the current study  investigated the use of Polyethylene Terephthalate (PET) as substitute for natural sand in concrete production. Locally sourced river sand was replaced with industrially ground waste PET in proportions of 4 to 20% at a step of 4% by the weight of natural sand whereas other concrete constituents (cement, granite, water-cement ratio and superplasticizer) were kept constant. A Grade M40 concrete with a mix proportion of 1:1:2:0.35 (cement: sand: granite: water-to-cement ratio) was used for all concrete mixes.  Concrete without PET represents the control. Fresh (Slump) and hardened (compressive, split tensile and flexural) properties of the produced concrete were assessed using standard testing methods. The results showed that the slump of concrete decreased by 1.8% and 12.5% with an increase in PET content from 0 to 20%. The 28-day compressive strength of concrete containing PET was lower than the control. However, concrete with 4% PET compared considerably well with control with the compressive strength value exceeding the target strength of 40 N/mm2 while concretes containing PET beyond 4% had compressive strength below the target strength. The split tensile strength of concrete containing 4% PET was higher than that of the control but exhibited lower flexural strength than the control at the age of 28 days. It was concluded that the reuse of PET as a substitute for natural sand as an alternative waste disposal solution for eco-friendly concrete development and attainment of a pollution-free environment is viable.

Influence of Limestone Powder on Performance of the Pre-Mixed Cement Mortar

2011 ◽  
Vol 306-307 ◽  
pp. 1096-1100
Author(s):  
Xiu Zhi Zhang ◽  
Chao Shun Han ◽  
Xue Yin
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Cement Mortar ◽  
Setting Time ◽  
Limestone Powder ◽  
Specific Density ◽  
Manufactured Sand

Effect of the different contents of limestone power (LSP) in manufactured-sand (MS) is investigated in respect of the workability, setting time and compressive strength. The results show that the contents in a certain range can significantly increase the consistency, Specific density of the fresh mortar, and improve comprehensive strength of the hardened mortar due to LSP deduced the porosity and improved the pore structure.

Fabrication of Porous Al2O3 Ceramics by Freeze Drying Technique and Annealing Treatment

2016 ◽  
Vol 848 ◽  
pp. 272-278 ◽  
Author(s):  
Sha Qiu ◽  
Yu Fei Tang ◽  
Kang Zhao
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Pore Size ◽  
Annealing Time ◽  
Open Porosity ◽  
Sucrose Solution ◽  
Annealing Treatment ◽  
Porous Ceramics ◽  
Crystalline Solid ◽  
Directional Freezing

Porous Al2O3 ceramics were fabricated by directional freezing and low pressure drying with sucrose solution as the cryogenic medium. The pore structure of the porous ceramics was changed by annealing in the environment of higher than the glass transition temperature of sucrose solution after directional freezing because of changing the size and distribution of crystalline solid. The effects of the annealing time on the pore structure, open porosity and mechanical property of porous ceramics were investigated. The results showed that the pore size of porous ceramics increased substantially with the increase of annealing time. The open porosity of porous ceramics changed slightly with the increase of annealing time, while the compressive strength of porous ceramics showed a trend of decrease. The pore size range of porous Al2O3 ceramics fabricated is from 6.0μm to 110.2μm, the range of porosity was 40.35%-64.58%, the compressive strength range of porous Al2O3 ceramics was from 25.9MPa-126.6MPa. The porous Al2O3 ceramics with different pore structure can be obtained by changing the annealing time.

scholarly journals Improvement of ANFIS Model for Prediction of Compressive Strength of Manufactured Sand Concrete

2019 ◽  
Vol 9 (18) ◽  
pp. 3841 ◽  
Author(s):  
Ly ◽  
Pham ◽  
Dao ◽  
Le ◽  
Le ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Mean Squared Error ◽  
Fuzzy Inference ◽  
Principal Component ◽  
Absolute Error ◽  
Anfis Model ◽  
Natural Sand ◽  
Inference System ◽  
Computing Technique ◽  
Manufactured Sand

Use of manufactured sand to replace natural sand is increasing in the last several decades. This study is devoted to the assessment of using Principal Component Analysis (PCA) together with Teaching-Learning-Based Optimization (TLBO) for enhancing the prediction accuracy of individual Adaptive Neuro Fuzzy Inference System (ANFIS) in predicting the compressive strength of manufactured sand concrete (MSC). The PCA technique was applied for reducing the noise in the input space, whereas, TLBO was employed to increase the prediction performance of single ANFIS model in searching the optimal weights of input parameters. A number of 289 configurations of MSC were used for the simulation, especially including the sand characteristics and the MSC long-term compressive strength. Using various validation criteria such as Correlation Coefficient (R), Root Mean Squared Error (RMSE), and Mean Absolute Error (MAE), the proposed method was validated and compared with several models, including individual ANFIS, Artificial Neural Networks (ANN) and existing empirical equations. The results showed that the proposed model exhibited great prediction capability compared with other models. Thus, it appeared as a robust alternative computing tool or an efficient soft computing technique for quick and accurate prediction of the MSC compressive strength.

scholarly journals Use of Recycled Tyre Rubber in Non-structural Concrete

2018 ◽  
Vol 203 ◽  
pp. 06001
Author(s):  
Muhammad Bilal Waris ◽  
Hussain Najwani ◽  
Khalifa Al-Jabri ◽  
Abdullah Al-Saidy
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Structural Concrete ◽  
Cement Ratio ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
Concrete Blocks

To manage tyre waste and conserve natural aggregate resource, this research investigates the use of waste tyre rubber as partial replacement of fine aggregates in non-structural concrete. The research used Taguchi method to study the influence of mix proportion, water-to-cement ratio and tyre rubber replacement percentage on concrete. Nine mixes were prepared with mix proportion of 1:2:4, 1:5:4 and 1:2.5:3; water-to-cement ratio of 0.25, 0.35 and 0.40 and rubber to fine aggregate replacement of 20%, 30% and 40%. Compressive strength and water absorption tests were carried out on 100 mm cubes. Compressive strength was directly proportional to the amount of coarse aggregate in the mix. Water-to-cement ratio increased the strength within the range used in the study. Strength was found to be more sensitive to the overall rubber content than the replacement ratio. Seven out of the nine mixes satisfied the minimum strength requirement for concrete blocks set by ASTM. Water absorption and density for all mixes satisfied the limits applicable for concrete blocks. The study indicates that mix proportions with fine to coarse aggregate ratio of less than 1.0 and w/c ratio around 0.40 can be used with tyre rubber replacements of up to 30 % to satisfy requirements for non-structural concrete.

scholarly journals Influence of Molarity and Chemical Composition on the Development of Compressive Strength in POFA Based Geopolymer Mortar

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
S. M. Alamgir Kabir ◽  
U. Johnson Alengaram ◽  
Mohd Zamin Jumaat ◽  
Afia Sharmin ◽  
Azizul Islam
Keyword(s):  
Compressive Strength ◽  
Blast Furnace Slag ◽  
Palm Oil Fuel Ash ◽  
Manufactured Sand ◽  
Granulated Blast Furnace Slag ◽  
Mix Proportion ◽  
Geopolymer Matrix ◽  
Fuel Ash ◽  
Oil Fuel ◽  
Furnace Slag

The investigation concerns the use of the optimum mix proportion of two locally available pozzolanic waste materials, namely, ground granulated blast furnace slag (GGBS) and palm oil fuel ash (POFA), together with metakaolin (MK) as binders. In addition, another local waste material, manufactured sand (M-sand), was used as a replacement for conventional sand in the development of green geopolymer mortar. Twenty-four mortar mixtures were designed with varying binder contents and alkaline activators. The oven dry curing was also kept consistent for all the mix proportions at a temperature of 65°C for 24 hours. The highest 28-day compressive strength of about 48 MPa was obtained for the mortar containing 20% of MK, 35% of GGBS, and 45% of POFA. The increment of MK beyond 20% leads to reduction of the compressive strength. The GGBS replacement beyond 35% also reduced the compressive strength. The entire specimen achieved average 80% of the 28-day strength at the age of 3 days. The density decreased with the increase of POFA percentage. The finding of this research by using the combination of MK, GGBS, and POFA as binders to wholly replace conventional ordinary Portland cement would lead to alternate eco-friendly geopolymer matrix.

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