scholarly journals Performance Evaluation of Soft Computing for Modeling the Strength Properties of Waste Substitute Green Concrete

2021 ◽  
Vol 13 (5) ◽  
pp. 2867
Author(s):  
Muhammad Izhar Shah ◽  
Muhammad Nasir Amin ◽  
Kaffayatullah Khan ◽  
Muhammad Sohaib Khan Niazi ◽  
Fahid Aslam ◽  
...  

The waste disposal crisis and development of various types of concrete simulated by the construction industry has encouraged further research to safely utilize the wastes and develop accurate predictive models for estimation of concrete properties. In the present study, sugarcane bagasse ash (SCBA), a by-product from the agricultural industry, was processed and used in the production of green concrete. An advanced variant of machine learning, i.e., multi expression programming (MEP), was then used to develop predictive models for modeling the mechanical properties of SCBA substitute concrete. The most significant parameters, i.e., water-to-cement ratio, SCBA replacement percentage, amount of cement, and quantity of coarse and fine aggregate, were used as modeling inputs. The MEP models were developed and trained by the data acquired from the literature; furthermore, the modeling outcome was validated through laboratory obtained results. The accuracy of the models was then assessed by statistical criteria. The results revealed a good approximation capacity of the trained MEP models with correlation coefficient above 0.9 and root means squared error (RMSE) value below 3.5 MPa. The results of cross-validation confirmed a generalized outcome and the resolved modeling overfitting. The parametric study has reflected the effect of inputs in the modeling process. Hence, the MEP-based modeling followed by validation with laboratory results, cross-validation, and parametric study could be an effective approach for accurate modeling of the concrete properties.

2014 ◽  
Vol 875-877 ◽  
pp. 619-623 ◽  
Author(s):  
Suppachai Sinthaworn ◽  
Wasan Teerajetgul ◽  
Attasit Sirivachiraporn

In this study, the workability, the compressive strength and the water penetration depth under pressure for concrete incorporate with quarry waste as fine aggregate were investigated. The mix proportions of concrete were set into two classes of water to cement ratio (w/c = 0.4, 0.6). The first class (C1), the mix proportion is 1.0:0.6:2.0:4.0 (Cement: Water: Fine: Coarse). And the second class (C2), the mix proportion is 1.0:0.4:1.5:3.0 and adding the superplasticizer 1% of cement weight. The natural river sand, which use in concrete, was partially replaced by quarry dust at the rates of 0% (no quarry dust), 50% and 100 % by weight of fine aggregate. The results show that concrete containing quarry wastes as fine aggregate decreased the workability and do not significantly affect the 28-day compressive strength whereas concrete incorporating with quarry dusts reduces the water penetration depth.


SCC is a concrete which has the ability to flow like liquid. This flowability of concrete is achieved by limiting the size of coarse aggregate content. Also 20% of the coarse aggregate is replaced by utilizing flyash inorder to increase the percentage of powder content..And due to the scarcity and unavailability of sand, an alternate is choosen to measure the rate of workability of SCC using quarry rock dust. The main property and strength of SCC depends on its workability[1] Hence workability tests and its relative compressive strength have been conducted to measure SCC specimens with fine aggregate and quarry rock dust. Fluidity of the paste can be improved by increasing the content of water-powder ratio and by adding super plasticizers. Segregation and blockages can be avoided by reducing the coarse aggregate content. A viscosity modifying agent (VMA) helps to reduce the changes in concrete properties[2]. Thus, relative proportions of ingredients need to be carefully determined to impart self leveling and self compacting properties to SCC in the fresh stage. Thus SCC specimens have been casted with quarry rock dust and fine aggregate using three different bases of superplasticizers(HRWRA) such as polycarboxyl, naphthalene and melamine bases and VMA. And its workability and strength properties have been evaluated by conducting different tests.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lisha Yu ◽  
Yang Zhao ◽  
Hailiang Wang ◽  
Tien-Lung Sun ◽  
Terrence E. Murphy ◽  
...  

Abstract Background Poor balance has been cited as one of the key causal factors of falls. Timely detection of balance impairment can help identify the elderly prone to falls and also trigger early interventions to prevent them. The goal of this study was to develop a surrogate approach for assessing elderly’s functional balance based on Short Form Berg Balance Scale (SFBBS) score. Methods Data were collected from a waist-mounted tri-axial accelerometer while participants performed a timed up and go test. Clinically relevant variables were extracted from the segmented accelerometer signals for fitting SFBBS predictive models. Regularized regression together with random-shuffle-split cross-validation was used to facilitate the development of the predictive models for automatic balance estimation. Results Eighty-five community-dwelling older adults (72.12 ± 6.99 year) participated in our study. Our results demonstrated that combined clinical and sensor-based variables, together with regularized regression and cross-validation, achieved moderate-high predictive accuracy of SFBBS scores (mean MAE = 2.01 and mean RMSE = 2.55). Step length, gender, gait speed and linear acceleration variables describe the motor coordination were identified as significantly contributed variables of balance estimation. The predictive model also showed moderate-high discriminations in classifying the risk levels in the performance of three balance assessment motions in terms of AUC values of 0.72, 0.79 and 0.76 respectively. Conclusions The study presented a feasible option for quantitatively accurate, objectively measured, and unobtrusively collected functional balance assessment at the point-of-care or home environment. It also provided clinicians and elderly with stable and sensitive biomarkers for long-term monitoring of functional balance.


2018 ◽  
Vol 928 ◽  
pp. 257-262 ◽  
Author(s):  
Trong Phuoc Huynh ◽  
Chao Lung Hwang ◽  
Si Huy Ngo

This paper presents the results of the experimental works to investigate the use of waste limestone from water treatment industry as fine aggregate in green concrete. Two concrete mixtures with a constant water-to-binder ratio of 0.3 were prepared for this investigation, in which, the normal concrete mixture was designed following the guidelines of ACI 211 standard, while the green concrete mixture was designed using densified mixture design algorithm (DMDA) technology. For comparison, both types of concrete samples were subjected to the same test program, including fresh properties, compressive strength, strength efficiency of cement, drying shrinkage, electrical surface resistivity, ultrasonic pulse velocity, and thermal conductivity. Test results indicate that both concrete mixtures showed the excellent workability due to the round-shape of waste limestone aggregate and the use of superplasticizer. In addition, the green concrete mixture exhibited a better performance in terms of engineering properties and durability in comparison with the normal concrete mixture. The results of the present study further support the recycling and reuse of waste limestone as fine aggregate in the production of green concrete.


2018 ◽  
Vol 203 ◽  
pp. 06001
Author(s):  
Muhammad Bilal Waris ◽  
Hussain Najwani ◽  
Khalifa Al-Jabri ◽  
Abdullah Al-Saidy

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.


2020 ◽  
Vol 230 ◽  
pp. 116929 ◽  
Author(s):  
Gloria M. Cuenca-Moyano ◽  
Jaime Martín-Pascual ◽  
María Martín-Morales ◽  
Ignacio Valverde-Palacios ◽  
Montserrat Zamorano

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