Geotechnical characteristics of recycled crushed brick blends for pavement sub-base applications

2012 ◽  
Vol 49 (7) ◽  
pp. 796-811 ◽  
Author(s):  
A. Arulrajah ◽  
J. Piratheepan ◽  
M.W. Bo ◽  
N. Sivakugan
Keyword(s):  
Recycled Concrete ◽  
Engineering Properties ◽  
Triaxial Tests ◽  
Crushed Rock ◽  
Dry Density ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Crushed Brick ◽  
Repeated Load ◽  
Repeated Load Triaxial

This paper presents the findings of a laboratory investigation on the characterization of recycled crushed brick when blended with recycled concrete aggregate and crushed rock for pavement sub-base applications. The engineering properties of the crushed brick blends were compared with typical state road authority specifications in Australia for pavement sub-base systems to ascertain the potential use of crushed brick blends in these applications. The experimental programme included particle-size distribution, modified Proctor compaction, particle density, water absorption, California bearing ratio (CBR), Los Angeles abrasion, pH, organic content, and repeated load triaxial tests. Laboratory tests were undertaken on mixtures of 10%, 15%, 20%, 25%, 30%, 40%, and 50% crushed brick blended with recycled concrete aggregate or crushed rock. The research indicates that up to 25% crushed brick could be safely added to recycled concrete aggregate and crushed rock blends in pavement sub-base applications. The repeated load triaxial test results on the blends indicate that the effects of crushed brick content on the mechanical properties in terms of permanent deformation and resilient modulus of both the recycled concrete aggregate and crushed rock blends were marginal compared to the effects on dry density and moisture content.

scholarly journals Shear Strength Characteristics of Recycled Concrete Aggregate and Recycled Tire Waste Mixtures from Monotonic Triaxial Tests

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7400
Author(s):  
Katarzyna Gabryś ◽  
Algirdas Radzevičius ◽  
Alojzy Szymański ◽  
Raimondas Šadzevičius
Keyword(s):  
Shear Strength ◽  
Construction Projects ◽  
Fine Fraction ◽  
Recycled Concrete ◽  
Engineering Properties ◽  
Triaxial Tests ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Angle Of Internal Friction ◽  
Anthropogenic Soil

Recycled concrete aggregate (RCA) is a promising substitute for natural aggregates and the reuse of this material can benefit construction projects both economically and environmentally. RCA has received great attention in recent years in the form of aggregate as well as a geotechnical material of sand size. Next to RCA, another recycled material, which reduces the waste volume and is a part of the present challenges in civil engineering, is tire waste. Despite the good engineering properties of recycled tire waste (RTW), its use is still limited, even after almost 30 years since they were first introduced. To broaden the applicability of reused concrete and rubber, a further understanding of their properties and engineering behavior is required. For this reason, the main subject of this paper is composite materials that consist of anthropogenic soil recycled concrete aggregate (RCA) and crushed pieces of recycled tire waste (RTW). In this study, a series of isotropic consolidated drained triaxial tests were undertaken to characterize the shear strength of eight mixtures of variable grain-size distribution, rubber inclusion (RC), and fine fraction (FF) content. The results show that the introduction of rubber waste leads to changes in the strength parameters of the tested mixtures. Improvements in RCA shear strength were observed, the largest for the mixture M7 with 10% of recycled tire waste. Similarly, the effect of fine fraction content on the angle of internal friction and cohesion was found. Dilation characteristics were observed in all analyzed composites. Based on the results of all tests performed, including physical, geometric, chemical, and mechanical properties of the created composites, it can be stated that the samples would meet local road authority requirements for sub-base applications.

Discrete element analysis of recycled concrete aggregate responses during repeated load triaxial testing

2020 ◽  
Vol 23 ◽  
pp. 100356 ◽  
Author(s):  
Arul Arulrajah ◽  
Hooman Baghban ◽  
Guillermo A. Narsilio ◽  
Suksun Horpibulsuk ◽  
Melvyn Leong
Keyword(s):  
Discrete Element ◽  
Recycled Concrete ◽  
Triaxial Testing ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Element Analysis ◽  
Repeated Load ◽  
Repeated Load Triaxial

scholarly journals Effects of pre-wetting aggregate on the properties of mortars made with recycled concrete and lightweight aggregates

2019 ◽  
Vol 24 (2) ◽  
Author(s):  
Lidiane Fernanda Jochem ◽  
Diego Aponte ◽  
Marilda Barra Bizinotto ◽  
Janaíde Cavalcante Rocha
Keyword(s):  
Lightweight Aggregate ◽  
Heat Of Hydration ◽  
Recycled Concrete ◽  
Partial Replacement ◽  
Dry Density ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Natural Aggregate ◽  
Entrained Air ◽  
Dimensional Instability

ABSTRACT This paper examines the suitability of partially replacing natural aggregate, sand, (NA) with recycled concrete aggregate (RCA) or lightweight aggregate (LWA) in mortars, under the hypothesis that pre-wetting aggregates would produce improvement in mortar properties. Fresh mortar properties such as density, entrained air content, consistency and heat of hydration, as well as hardened mortar properties such as dry density, compressive and flexural strength, and dimensional instability at 0% and 100% saturation were determined. The results show that mortars made with natural aggregate (75%) and recycled concrete aggregate (25%) have similar properties to mortars made with only natural aggregate (100%) and that pre-wetting the aggregates does not influence the properties of mortars significantly. Therefore, partial replacement with recycled concrete aggregate is a viable alternative for producing mortar.

scholarly journals Development of a Correlation between the Resilient Modulus and CBR Value for Granular Blends Containing Natural Aggregates and RAP/RCA Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Muhammad Arshad
Keyword(s):  
Statistical Analysis ◽  
Resilient Modulus ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Triaxial Tests ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt ◽  
Serviceable Life ◽  
Natural Aggregates ◽  
Repeated Load Triaxial

Limited supplies of natural aggregates for highway construction, in addition to increasing processing costs, time, and environmental concerns, have led to the use of various reclaimed/recycled materials. Reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) have prospective uses in substantial amounts in base and subbase layers of flexible pavement in order to overcome the increasing issue of a shortage of natural aggregates. This research presents the development of an empirical model for the estimation of resilient modulus value (MR) on the basis of CBR values using experimental results obtained for 52 remoulded granular samples containing natural aggregates, RCA, and RAP samples. Statistical analysis of the suggested model shows promising results in terms of its strength and significance when t-test was applied. Additionally, experimental results also show that MR value increases in conjunction with an increase in RAP contents, while the trend for the CBR value is the opposite. Statistical analysis of simulation results using PerRoad and KenPave demonstrates that addition of RAP contents in the subbase layer of flexible pavements significantly improves its performance when considering resistance against rutting and fatigue. However, results of repeated load triaxial tests show that residual accumulative strain under a certain range of loading conditions increases substantially due to the addition of RAP materials, which may be disadvantageous to the serviceable life of the whole pavement structure.

Neural Network Modeling of Anisotropic Aggregate Behavior from Repeated Load Triaxial Tests

1998 ◽  
Vol 1615 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Erol Tutumluer ◽  
Umit Seyhan
Keyword(s):  
Neural Networks ◽  
Triaxial Tests ◽  
Neural Network Modeling ◽  
Dry Density ◽  
Prediction Ability ◽  
Aggregate Properties ◽  
Target Values ◽  
Ann Models ◽  
Repeated Load ◽  
Repeated Load Triaxial

Determining horizontal specimen response in a repeated load triaxial test is essential to properly characterize the directional dependency of unbound aggregate resilient behavior under anisotropic loading conditions. Recent research has applied artificial neural networks (ANNs) for predicting, in the absence of lateral deformation data, the anisotropic stiffness properties of granular materials from standard AASHTO tests. Feed-forward backpropagation-type neural networks were successfully trained with two triaxial stresses (confining pressure and applied deviator stress), measured vertical deformation, and two aggregate properties (compacted dry density and crushed particle percentage) used as input variables. The output variables were the horizontal and shear moduli for which the actual (target) values were derived and computed from test results. The ANN models predicted the two moduli, with mean errors of less than 3 percent compared with those computed by using experimental stresses and strains. Both the applied stress state and the aggregate properties were found to affect the generalization and thus the prediction ability of the ANN models.

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