Sustainability-based decision support framework for choosing concrete mixture proportions

Abstract

A framework is proposed, along with two objective indices, for the selection of concrete mixture proportions based on sustainability criteria. The indices combine energy demand and long-term strength as energy intensity, and carbon emissions and durability parameters as A-indices, which represent the apathy toward these essential features of sustainability. The decision support framework is demonstrated by considering a set of 30 concretes with different binders, including ordinary portland cement (OPC), fly ash, slag and limestone calcined clay cement (LC3). In addition to the experimental data on compressive strength, chloride diffusion and carbonation, life cycle assessment has been performed for the concretes considering typical situations in South India. The most sustainable of the concretes studied here, for service life limited by chloride ingress, are those with LC3, OPC replaced by 50% slag, and ternary blends with 20% each of slag and fly ash. In the case of applications where carbonation is critical, the appropriate concretes are those with OPC replaced by 15-30% slag or 15% fly ash, or with ternary blends having 20% slag and 20% Class F fly ash.

Use of supplementary cementitious materials (SCMs) in reinforced concrete systems – Benefits and limitations

“…Partial substitution of OPC with SCMs can lead to significant reduction in the CO2 emissions associated with the production of cement; and hence, the production of concrete. In order to quantify the positive aspects related to the carbon footprint and environmental impact of concretes with blended binders, extensive investigations have been undertaken at IIT Madras using life cycle assessment (LCA) performed with data from various cement plants in India (Gettu et al, 2016(Gettu et al, , 2018(Gettu et al, , 2019. Figure 15 shows the CO2 emissions obtained for one of the case studies considering M50 concretes.…”

A proposed performance based approach for life cycle assessment of reinforced blended cement concrete

“…Gutierrez et al (2017) devised a FU that divides the volume of cement by the number of years of durability. Furthermore, an accurate methodology was proposed by Gettu et al (2018), where the test results for the carbonation, chloride penetration and compressive strength of thirty different BC concrete mixes were incorporated into two FU. In the first FU (Energy intensity) the volume is divided by the compressive strength indicating performance, and in the second FU (A-indices) the carbonation and chloride penetration parameters are converted into expected service life predictions.…”

LEED Study of Green Lightweight Aggregates in Construction

“…The rapid increase in urbanization in developing countries is ultimately coupled with an unprecedented growth rate of the global building sector [1,2] With this, the world is expected to reach an alarming approximate area of 230 billion square meters of new construction over the next 40 years [1]. Global environmental awareness has gained momentum over the last few decades, due to the increasing emergence of a wide range of environmental concerns, such as climate change, deforestation, pollution, energy security, water stress and pollution, and shortage of natural resources [3]. The application of sustainability principles within the construction industry has been advocated by researchers within the past decades [4], which has become of exceeding relevance at the present time due to the increase in global cement production, and related carbon dioxide emissions, in addition to the rising demand for natural resources, such as water, aggregate, limestone, and energy [3].…”

“…Global environmental awareness has gained momentum over the last few decades, due to the increasing emergence of a wide range of environmental concerns, such as climate change, deforestation, pollution, energy security, water stress and pollution, and shortage of natural resources [3]. The application of sustainability principles within the construction industry has been advocated by researchers within the past decades [4], which has become of exceeding relevance at the present time due to the increase in global cement production, and related carbon dioxide emissions, in addition to the rising demand for natural resources, such as water, aggregate, limestone, and energy [3]. Moreover, the industry is responsible for a significant volume Sustainability 2021, 13, 1395 2 of 18 of construction-related waste and emissions, which accounts for 13-30% of global waste generation [5], and 39% of energy-related carbon dioxide emissions [1].…”