Study on Production of Concrete Small Hollow Block with Recycled Aggregate

2013 ◽  
Vol 662 ◽  
pp. 352-355 ◽  
Author(s):  
Qi Jin Li ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Recycled Aggregate ◽  
Grain Composition ◽  
Construction Waste ◽  
Natural Aggregate ◽  
Hollow Block ◽  
Compressive Strength Of Concrete ◽  
Chemical Activator

The construction waste was processed into recycled aggregate and was used to substitute for natural aggregate to produce concrete small hollow block with grade of MU7.5. The effect of grain composition, replacement ratios and chemical activator of recycled aggregate on compressive strength of concrete small hollow block was studied. The results shows that through optimized grain composition of recycled aggregate and mixed with appropriate chemical activator, the compressive strength of concrete small hollow block with 100% recycled aggregate can be satisfied with the requirement of MU7.5 concrete small hollow block.

Effect of wastes and admixtures on compressive strength of concrete

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rachit Sharma
Keyword(s):  
Compressive Strength ◽  
Concrete Specimen ◽  
Construction And Demolition Waste ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Construction Waste ◽  
Aggregate Concrete ◽  
Content Type ◽  
Natural Aggregate ◽  
Compressive Strength Of Concrete

Purpose This paper presents the effects of replacing fine aggregate (FA) with waste foundry sand (WFS) in natural aggregate and construction waste aggregate concrete specimens without and with superplasticizer (SP), silica fume (SF) and fiber (F) to solve the disposal problems of various wastes along with saving the environment. This study aims to investigate the effect of construction waste, WFS along with additives on the stress-strain behavior and development of compressive strength with age. Design/methodology/approach The various concrete specimen were prepared in mix proportion of 1: 2: 4 (cement (C): sand: coarse aggregate). The water-cement ratio of 0.5 (decreased by 10% for samples containing SP) to grading 1: 2: 4 under air-dry condition was adopted in the preparation of concrete specimens. The compressive strength of various concrete specimen were noticed for 3, 7 and 28 days by applying load through universal testing machine. Findings Upon adding construction and demolition waste aggregates, the compressive strength of concrete after 28 days was comparable to that of the control concrete specimen. An enhancement in the value of compressive strength is perceived when FA is replaced with WFS to the extent of 10%, 20% and 30%. If both construction and demolition waste aggregate and WFS replacing FA are used, the compressive strength increases. When FA is interchanged with WFS in natural aggregate or construction demolition waste aggregate concrete including usage of SF or F, the compressive strength improves significantly. Further, when construction and demolition waste aggregate and WFS replacing FA including SP are used, the compressive strength improves marginally compared to that of control specimen. The rate of strength development with age is observed to follow similar trend as in control concrete specimen. Therefore, construction and demolition waste and or WFS can be used effectively in concrete confirming an improvement in strength. Originality/value The utilization of these wastes in concrete will resolve the problem of their disposal and save the environment.

scholarly journals Predicting Compressive Strength of Concrete Containing Recycled Aggregate Using Modified ANN with Different Optimization Algorithms

2021 ◽  
Vol 11 (2) ◽  
pp. 485
Author(s):  
Amirreza Kandiri ◽  
Farid Sartipi ◽  
Mahdi Kioumarsi
Keyword(s):  
Compressive Strength ◽  
Optimization Algorithms ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Tree Model ◽  
Grasshopper Optimization Algorithm ◽  
Compressive Strength Of Concrete ◽  
Grasshopper Optimization ◽  
Artificial Neural Network Ann ◽  
Industry Needs

Using recycled aggregate in concrete is one of the best ways to reduce construction pollution and prevent the exploitation of natural resources to provide the needed aggregate. However, recycled aggregates affect the mechanical properties of concrete, but the existing information on the subject is less than what the industry needs. Compressive strength, on the other hand, is the most important mechanical property of concrete. Therefore, having predictive models to provide the required information can be helpful to convince the industry to increase the use of recycled aggregate in concrete. In this research, three different optimization algorithms including genetic algorithm (GA), salp swarm algorithm (SSA), and grasshopper optimization algorithm (GOA) are employed to be hybridized with artificial neural network (ANN) separately to predict the compressive strength of concrete containing recycled aggregate, and a M5P tree model is used to test the efficiency of the ANNs. The results of this study show the superior efficiency of the modified ANN with SSA when compared to other models. However, the statistical indicators of the hybrid ANNs with SSA, GA, and GOA are so close to each other.

Study on Preparation of Solid Concrete Brick with Recycled Aggregate

2013 ◽  
Vol 648 ◽  
pp. 108-111
Author(s):  
Qi Jin Li ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Mass Fraction ◽  
Recycled Aggregate ◽  
Preparation Process ◽  
Mass Ratio ◽  
Construction Waste ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Optimal Value

The construction waste was processed into recycled aggregate to produce solid construction waste brick with grade of MU20. The preparation process of recycled aggregate and the optimal value of mass ratio of water to cement (water cement ratio) and mass ratio of recycled aggregate to cement was studied. The results shows that when the water cement ratio is 0.86 and the mass ratio of recycled aggregate to cement is 5.5 and the dosage of activator is 0.25% (mass fraction with recycled aggregate), the compressive strength of sample is 22.5MPa and can be satisfied with the requirement of MU20 solid concrete brick.

scholarly journals Probabilistic Conversion of the Compressive Strength of Cubes to Cylinders of Natural and Recycled Aggregate Concrete Specimens

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 280 ◽  
Author(s):  
João Pacheco ◽  
Jorge de Brito ◽  
Carlos Chastre ◽  
Luís Evangelista
Keyword(s):  
Compressive Strength ◽  
Conversion Factor ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Structural Behaviour ◽  
Aggregate Concrete ◽  
Coarse Aggregates ◽  
Natural Aggregate ◽  
Using Data ◽  
The Relationship

This paper investigates the effect of recycled coarse aggregate incorporation on the relationship between 150 mm cubic and Փ 150 mm cylindrical compressive strength (the reference strength of standards) by comparing data from recycled and natural aggregate concrete compositions in which both cubes and cylinders were tested. A conversion factor from cubic to cylindrical strength is proposed in two versions: A deterministic and a probabilistic one. Such factor has not been studied before and researchers have been converting cubic data as if natural aggregate concrete were tested. The probabilistic factor is intended for reliability analyses on the structural behaviour of recycled aggregate concrete using data from laboratory cube tests. It was found that the incorporation of recycled coarse aggregates sourced from concrete waste significantly decreases the expected value of the factor but the factor’s scatter is relatively unaffected.

scholarly journals Effect of Iron Filings on the Mechanical Properties of Different Types of Sustainable Concrete

2018 ◽  
Vol 12 (1) ◽  
pp. 441-457 ◽  
Author(s):  
Sahar Jabbar Alserai ◽  
Wissam Kadhim Alsaraj ◽  
Zina Waleed Abass
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Indirect Tensile Strength ◽  
Recycled Aggregate ◽  
Geopolymer Concrete ◽  
Normal Concrete ◽  
Natural Aggregate ◽  
Indirect Tensile

Introduction:One of Iraq’s major environmental problems is a large amount of residual iron produced by the industrial sector, which is stored in domestic waste and landfills. The reuse of construction waste gives two aims, the first is to remove large quantities of pollution resulted from these waste, the second provides cheap resources for concrete aggregates.Methods:This study conducted a series of experiments and tests to test the feasibility of reusing this iron slag and recycled concrete aggregate in concrete mixtures. Different percentages of iron filings were used in the concrete mixture at 0, 0.5%, 0.75% and 1%. Tests are done to evaluate the quality of cast iron concrete which include compressive strength (fcu), flexural strength (fr), indirect tensile strength (ft), SEM and modulus of elasticity (Ec) for four sustainable concretes.Results and Conclusion:The results show that the iron filings amount is increased to 1.0% which resulted in increasing percentage of compressive strength (fcu), flexural strength (fr), indirect tensile strength (ft), SEM and modulus of elasticity (Ec) with 10%, 32%, 42% and 11% for Geopolymer Concrete with Recycled Aggregate (GCRA), 9%, 52%,31% and 17% for geopolymer concrete with natural aggregate (GCNA), 10%, 19%,26% and 12% for Normal Concrete with Natural Aggregate (NCNA) and 23%, 19%, 67% and 14% for Normal Concrete with Recycled Aggregate (NCRA), respectively.

scholarly journals Evaluating the Compressive Strength of Concrete Containing Recycled Aggregate in Different Curing Conditions

2021 ◽  
Vol 11 (2) ◽  
pp. 127-136
Author(s):  
Sadaf Noshin ◽  
M. Adil Khan ◽  
M. Salman ◽  
M. Shahzad Aslam ◽  
Haseeb Ahmad ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Curing Conditions ◽  
Normal Water ◽  
Water Curing ◽  
Compressive Strength Of Concrete

Abstract In construction industry, demolished construction waste is recently used as reprocessed aggregate to produce environmentally friendly concrete which is a good substitute to normal crush due to increased demand of ecological growth and conservation benefits. Though, the properties of recycled aggregate concrete are smallest as compared to concrete produced from natural aggregate and these properties can be enhanced by adding some materials having cementitious properties. Rice husk ash (RHA) is used as partial replacement of cement in recycled aggregate concrete to improve the properties as well as to conserve the natural resources. The elementary purpose of this investigation is to determine the compressive strength of concrete by the replacement of cement with different percentages of rice husk ash such as 0%, 7.5%, 10%, 12.5%, 15%, and 17.5% respectively with different curing conditions. For the experimental program approximate 198 cylinders (18 for rapid curing, 90 for normal water curing and 90 for acid curing) are casted with the mix proportion of 1:2:4 and water to cement ratio of 0.50 whereas curing is done at the ages of 3,7,14,21 and 28 days. Various experiments are performed on fresh and hardened concrete to determine the effects of rice husk ash on recycled aggregate concrete with different curing conditions. Linear regression analysis is carried out to determine the compressive strength of concrete. It is pragmatic from the slump test results that the workability of recycled aggregate concrete is decreased by increasing the quantity of rice husk ash. This reduction in slump is due to high water absorption of recycled aggregates and rice husk ash. Further, the compressive strength of recycled aggregate concrete with normal and acid curing is decreased by increasing the percentages of rice husk ash. It is also observed that at 28- days of normal water curing for mix M1,M2,M3,M4,M5 and M6 the compressive strength is increased by 0.96%, 2.74% 1.45%,4.50%,4.23% and 4.22% respectively as compared to the compressive strength values at 28 days of acid water curing. Therefore, it is concluded that recycled aggregate concrete with 10 to 12% of rice husk ash is suitable for properties of concrete. The acid water curing has negative impacts on hardened properties of concrete as it reduced the compressive strength of concrete as compared to normal water curing.

scholarly journals Modelling the Influence of Waste Rubber on Compressive Strength of Concrete by Artificial Neural Networks

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 561 ◽  
Author(s):  
Marijana Hadzima-Nyarko ◽  
Emmanuel Karlo Nyarko ◽  
Naida Ademović ◽  
Ivana Miličević ◽  
Tanja Kalman Šipoš
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Compressive Strength ◽  
Artificial Neural Networks ◽  
Reliable Prediction ◽  
Network Modelling ◽  
Natural Aggregate ◽  
Waste Rubber ◽  
Compressive Strength Of Concrete ◽  
Enormous Number

One of the major causes of ecological and environmental problems comes from the enormous number of discarded waste tires, which is directly connected to the exponential growth of the world’s population. In this paper, previous works carried out on the effects of partial or full replacement of aggregate in concrete with waste rubber on some properties of concrete were investigated. A database containing 457 mixtures with partial or full replacement of natural aggregate with waste rubber in concrete provided by different researchers was formed. This database served as the basis for investigating the influence of partial or full replacement of natural aggregate with waste rubber in concrete on compressive strength. With the aid of the database, the possibility of achieving reliable prediction of the compressive strength of concrete with tire rubber is explored using neural network modelling.

Influence of Aggregates on Cracking Sensitivity of Concrete

2012 ◽  
Vol 204-208 ◽  
pp. 3299-3302 ◽  
Author(s):  
Xia Chen ◽  
Jian Jun Yan ◽  
Hua Quan Yang
Keyword(s):  
Compressive Strength ◽  
Stress Test ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Test Machine ◽  
Test Results ◽  
Concrete Cracking ◽  
Natural Aggregate ◽  
Compressive Strength Of Concrete ◽  
Cracking Sensitivity

Concrete cracking sensitivity made from different aggregates was compared with employment of advanced temperature and stress test machine by tracking thermal and stress development of concrete with age and elements distribution in interfacial transition zone of each concrete was explored by SEM and EDS. Test results indicated that compressive strength of concrete made from basalt and limestone was greater than diorite and natural aggregate and crack resistance of concrete based on cracking sensitivity comparison in terms of cracking temperature varying from minus 0.3°C to minus 2.5°C as diorite, basalt, limestone and natural aggregate. Elements Ca and Mg were apparently accumulated in vicinity of ITZ and some reaction between limestone and cement matrix might have taken place which blurred the boundary between aggregates and cement matrix.

Microscopic Analysis and Experimental Research on Thermal Mechanical Behavior of Natural Aggregate Concrete

2010 ◽  
Vol 129-131 ◽  
pp. 1039-1042
Author(s):  
H.Q. Yan ◽  
Q.Y. Wang
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Microscopic Analysis ◽  
Test Methods ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Strength Analysis ◽  
Aggregate Concrete ◽  
Natural Aggregate

Reinforced concrete construction is very common recently and extensively used both in industrial and commercial buildings. With the gradual rise in occurrences of fire accidents in recent years, a more thorough and quantitative understanding of the damage phenomenon in concrete structures is required. However, the mechanical behavior of concrete could actually be more complex under high temperature conditions than at room temperature. Restoration and reinforcement of the structures exposed to fire may have to be based on residual strength analysis and therefore require a correlation between temperature and mechanical properties. Thus, in order to meet the modern challenges of rapid engineering advances and societal development, further research on the concrete material and its structural behavior at high temperatures becomes extremely important. The present paper deals with investigations on the effect of high temperature exposure on the compressive strength of natural aggregate concrete. Experiments were conducted to study the compressive strength variations with increasing temperatures, up to 700 °C, and the subsequent cooling modes such as natural and spray cooling. Results show that the compressive strength gradually decreases with increasing temperatures. And micro-structural observations of the concrete specimens by means of scanning electron microscopy (SEM) were obtained. These test methods and results can be used for analyzing and investigating the behavior of recycled aggregate concrete with increasing temperatures.

Research on the Intensity Formula of Recycled Concrete Based on Crushed Index

2012 ◽  
Vol 174-177 ◽  
pp. 366-369
Author(s):  
Yu Dan Jiang ◽  
Guo Hui Gai ◽  
Wen Yan Meng
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Replacement Rate ◽  
Engineering Applications ◽  
Natural Aggregate

In order to obtain the intensity formula of recycled concrete, effects of crushed index of recycled aggregate, crushed index of natural aggregate and replacement rate of recycled aggregate on compressive strength of recycled concrete are discussed in this paper. Based on the results of recycled concrete with different replacement rate of recycled aggregate, the intensity formula of recycled concrete is proposed. It can provide references for engineering applications.

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