scholarly journals Sustainability Assessment of Using Recycled Aggregates in Concrete Block Pavements

2020 ◽  
Vol 12 (10) ◽  
pp. 4313 ◽  
Author(s):  
Md Mizanur Rahman ◽  
Simon Beecham ◽  
Asif Iqbal ◽  
Md Rajibul Karim ◽  
Abu Taher Zillur Rabbi

The mechanistic design of a concrete block pavement (CBP) can be very complicated and often requires the use of computer programs. This paper presents a new mechanistic-empirical method, which is implemented in a computer program (DesignPave) that calculates base course/sub-base thicknesses for a range of design inputs such as traffic load, interlocking properties, and material stiffness. A range of virgin and recycled unbound granular materials were also experimentally tested to characterize them for possible use as base course or sub-base materials. Combining the new mechanistic-empirical method and the range of base course/sub-base course materials (virgin and recycled aggregates), it was found that while a CBP containing recycled aggregates did not offer a significant direct financial benefit based on the characteristics or material costs, the associated environmental benefits were very high.

2019 ◽  
Vol 17 (1) ◽  
pp. 23-39
Author(s):  
Simone Wurster ◽  
Luana Ladu ◽  
Dhandy Arisaktiwardhana

Communicating the related environmental benefits of bio-based products to consumers represents a key component of their market uptake. In this regard, the use of ecolabels ISO 14024 Type I play a crucial role. This article identifies and analyzes different criteria proposed by ecolabels for conducting a sustainability assessment of bio-based products considering its entire lifecycle. A comparison of the selected criteria with existing indicators ruled out by the SDGs is proposed. Through expert consultation, the suitability of existing ecolabel criteria for bio-based products has been tested for four applications of biobased products: food packaging from PLA; biobased automotive components; bio-based mulch film; and bio-based insulation material.


2021 ◽  
Vol 6 (11) ◽  
pp. 159
Author(s):  
Ricardo Infante Gomes ◽  
David Bastos ◽  
Catarina Brazão Farinha ◽  
Cinthia Maia Pederneiras ◽  
Rosário Veiga ◽  
...  

Construction and demolition wastes (CDW) are generated at a large scale and have a diversified potential in the construction sector. The replacement of natural aggregates (NA) with CDW recycled aggregates (RA) in construction materials, such as mortars, has several environmental benefits, such as the reduction in the natural resources used in these products and simultaneous prevention of waste landfill. Complementarily, CDW have the potential to capture CO2 since some of their components may carbonate, which also contributes to a decrease in global warming potential. The main objective of this research is to evaluate the influence of the exposure of CDW RA to CO2 produced in cement factories and its effect on mortars. Several mortars were developed with a volumetric ratio of 1:4 (cement: aggregate), with NA (reference mortar), CDW RA and CDW RA exposed to high levels of CO2 (CRA). The two types of waste aggregate were incorporated, replacing NA at 50% and 100% (in volume). The mortars with NA and non-carbonated RA and CRA from CDW were analysed, accounting for their performance in the fresh and hardened states in terms of workability, mechanical behaviour and water absorption by capillarity. It was concluded that mortars with CDW (both CRA and non-carbonated RA) generally present a good performance for non-structural purposes, although they suffer a moderate decrease in mechanical performance when NA is replaced with RA. Additionally, small improvements were found in the performance of the aggregates and mortars with CRA subjected to a CO2 curing for a short period (5 h), while a long carbonation period (5 d) led to a decrease in performance, contrary to the results obtained in the literature that indicate a significant increase in such characteristics. This difference could be because the literature focused on made-in-laboratory CDW aggregates, while, in this research, the wastes came from real demolition activities, and were thus older and more heterogeneous.


2022 ◽  
pp. 316-334
Author(s):  
Simone Wurster ◽  
Luana Ladu ◽  
Dhandy Arisaktiwardhana

Communicating the related environmental benefits of bio-based products to consumers represents a key component of their market uptake. In this regard, the use of ecolabels ISO 14024 Type I play a crucial role. This article identifies and analyzes different criteria proposed by ecolabels for conducting a sustainability assessment of bio-based products considering its entire lifecycle. A comparison of the selected criteria with existing indicators ruled out by the SDGs is proposed. Through expert consultation, the suitability of existing ecolabel criteria for bio-based products has been tested for four applications of biobased products: food packaging from PLA; biobased automotive components; bio-based mulch film; and bio-based insulation material.


2014 ◽  
Vol 69 (7) ◽  
pp. 1526-1533 ◽  
Author(s):  
Luis A. Sañudo-Fontaneda ◽  
Susanne M. Charlesworth ◽  
Daniel Castro-Fresno ◽  
Valerio C. A. Andres-Valeri ◽  
Jorge Rodriguez-Hernandez

Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the ‘Laboratorio Caminos Santander’ permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance.


2013 ◽  
Vol 860-863 ◽  
pp. 1270-1273 ◽  
Author(s):  
Fu Jun Wang ◽  
Jing Luo ◽  
Hui Rong Zhu

Coal gangue, acting as the solid skeleton of pavement base materials, can efficiently reduce the drying shrinkage. Additionally, similar to fly ash in mixture material, gangue can react with lime (so called pozzolanic reaction), resulting in the formation of pavement base with a certain strength, good water stability and frost resistance, are good overall at the grass-roots level. Many cities in our country has gradually tried to use different kinds of industrial waste residue instead of sand to prepare the pavement base materials. This way, not only the waste residue is recycled, the lack of sand aggregates in road construction can also be overcome, which facilitate technical and economic growths.


1979 ◽  
Vol 16 (1) ◽  
pp. 78-89 ◽  
Author(s):  
P. M. Gifford ◽  
J. E. Gillott

Sulphur-bound soils and a lightweight aggregate sulphur concrete have been studied for potential use as structural frost insulating base materials in roadway construction. Sulphur-bound materials show rapid strength gain and sulphur has a low thermal conductivity (0.27 W/(m ∙ K)). Laboratory studies have shown, however, that, unless specially treated, sulphur-bound soil that contains significant swelling clay disintegrates in water. The laboratory studies were more favourable for the lightweight aggregate sulphur concrete and this material was used as a base course in two test sections of roadway. The test sections and a control section instrumented with thermocouples to measure temperatures to depths of 1.52 m were monitored for 6 winter months. A Dynaflect deflection apparatus was used for structural assessment. It was found that both frost penetration and the length of the subgrade freezing period were reduced and that the structural integrity of the pavement system was improved when lightweight aggregate sulphur concrete was introduced into the base course of the roadway.


2014 ◽  
Vol 13 (4) ◽  
pp. 153-160
Author(s):  
Piotr Koźlarek

Polish road network is made up of 95% local roads. Their technical condition is much worse in comparison to motorways and national roads network. The lack of financial resources is one of the main reasons for this situation. That is why there is a continuous search for technologies, that allow for fast and cheap pavement repair or modernization. The monolayer asphalt pavement is such a solution offering in addition to cost effectiveness and shorter construction time, also an increased durability. Our western neighbors developed the technical regulations for this technology under the name "Asphalttragdeckschicht" which is marked as AC 16 TD. In direct translation "Asphalttragdeckschicht" means supporting wearing course / base layer. The monolayer asphalt pavement consists of a single layer with thickness between 5 to 10 cm made of HMA that links the functions of two layers – asphalt base course and asphalt wearing course. Thanks to this, the monolayer is resistant to environmental conditions and provides an adequate bearing capacity for a given traffic load. Insufficient funding and the impossibility to put the street out of operation were the bases for the investor’s decision to build a 220m section of road pavement using the monolayer pavement technology in Pruszków near Warsaw. This project gave the possibility to learn and gain an experience with a new western technology applied to Polish reality.


2021 ◽  
Author(s):  
Huan Chen

Different approaches are usually taken when designing flexible and rigid pavement: the rigid concrete slab carries major portion of the traffic load; while for flexible pavement, external loads are distributed to the subgrade because of the relatively low modulus of elasticity of asphalt layer comparing to concrete in the case of rigid pavement. Pavement engineering has gone through major developments; the transition from Empirical Design Method to Mechanistic-Empirical Methods is becoming a near-future trend. The Mechanistic-Empirical Method has two components: (1) stress, strain and deflection are calculated based on analyzing mechanical characteristics of materials; (2) critical pavement distresses are quantitatively predicted by experimental calibrated equations. Hence, stress analysis has become an important role in pavement engineering. The most practical and widely used stress analysis method for flexible pavement is Burmister's Elastic Layered Theory; and for analyzing rigid pavement is Finite Element Method. KENSLABS and STAAD-III are both Finite Element software; KENSLABS is designed specifically for concrete pavement stress analysis, therefore it is more user-frielndly for pavement design; STAAD-III is more suitable for general plane and space structures. The project compares the use of both software for stress analysis in rigid pavement in term of simplicity and precision.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2651
Author(s):  
Francisco Agrela ◽  
Francisco González-Gallardo ◽  
Julia Rosales ◽  
Javier Tavira ◽  
Jesús Ayuso ◽  
...  

The application of recycled aggregates (RA) from construction and demolition waste and crushed concrete blocks is a very important challenge for the coming years from the environmental point of view, in order to reduce the exploitation of natural resources. In Spain, the use of these recycled materials in the construction of road bases and sub-bases is growing significantly. However, presently, there are few studies focused on the properties and behavior of RA in civil works such as road sections or seaport platforms. In this work, two types of RA were studied and used in a complete real-scale application. Firstly, recycled concrete aggregates (RCA) were applied in the granular base layer under bituminous superficial layers, and secondly mixed recycled aggregates (MRA) which contain a mix of ceramic, asphalt, and concrete particles were applied in the granular subbase layer, under the base layer made with RCA. Both RA were applied in a port loading platform in Huelva, applying a 100% recycling rate. This civil engineering work complied with the technical requirements of the current Spanish legislation required for the use of conventional aggregates. The environmental benefits of this work have been very relevant, and it should encourage the application of MRA and RCA in civil engineering works such as port platforms in a much more extended way. This is the first and documented real-scale application of RA to completely build the base and sub-base of a platform in the Huelva Port, Spain, replacing 100% of natural aggregates with recycled ones.


Sign in / Sign up

Export Citation Format

Share Document