On-demand | Concrete Innovations

Less Clinker in Cement, Less Paste in Concrete: A Two‐fold Strategy Towards Decarbonization

Franco Zunino, Physical Chemistry of Building Materials, Institute for Building Materials, ETH Zürich, Switzerland

Concrete is by a substantial margin the most widely used construction material. Projections indicate that the demand for concrete it will continue to increase to sustain the development of emerging economies. This paper presents a new perspective of low‐carbon concrete by refocusing on the actual final product, highlighting the tremendous CO2 saving opportunities of reducing the total paste volume of concrete while simultaneously using high performance, low‐clinker cements in the so‐called two‐fold strategy (low clinker content, low paste volume concrete formulations). Different aspects of low paste volume concrete formulations are discussed based on a combination of published and new concrete performance data, showing the potential for CO2 savings of the strategy and the technical opportunities to retain the robustness and reliability that make concrete such a versatile and widely used material. Chemical admixtures play a crucial role in reaching those objectives, as they enable to reduce the cement content while retaining the needed workability (slump and slump retention) for each application. The key issues relating to using those admixtures in low carbon concrete are highlighted.

Product Spotlight - Heidelberg Materials

Slag Cement, Today’s Strongest Carbon Reduction Tool

Larry Rowland, Sustainability Market Manager, Heidelberg Materials

Heidelberg Materials has the industry’s most aggressive carbon reduction targets. To achieve our Sustainability Commitments 2030, we are improving manufacturing efficiencies, applying carbon capture utilization and storage technology, and expanding our product line offerings to become the largest slag cement supplier in North America. Slag cement is an efficient, proven, low carbon, supplementary cementitious material that improves concrete performance. This program will highlight some of the many benefits this material delivers and use EPD data and specific project case study information to demonstrate why slag cement is considered the strongest tool for decarbonizing concrete mixtures on a broad scale.

Product Spotlight - Climate Earth

EPD Advantage Pro™ - The first EPD Information Management System

Chris Erickson, CEO and co-founder, Climate Earth

Carbon as a procurement metric is a game changer for how concrete is evaluated and purchased. As sustainability benchmarks tighten, producers grapple with balancing constructability and carbon requirements. In this session you will learn how EPD Advantage Pro transforms EPD data into strategic intelligence. With company and plant-level analytics, it empowers producers to navigate their EPD portfolio, assess underperforming plants, and bid precisely ensuring every low carbon project gets the right mixes.

SESSION 21: JUNE 19, 2024

DECARBONIZATION STRATEGIES

Improving the Efficiency of Concrete Structural Design through Alternative Reinforcement: A Serviceability Based Design Approach

Dr. Barzin Mobasher, PhD. PE. FACI, FRILEM, Professor, School of Sustainable Engineering and Built Environment, Arizona State University, Tempe, AZ

One of the most inefficient and unsustainable guidelines for structural design of concrete is to ignore the potential for tensile load-carrying capacity of concrete. When dealing with concrete brittleness, our traditional approach is to use more reinforcing steel to carry tensile loads leading to larger volumes of concrete and steel, resulting in reduced durability and increased carbon footprint. This presentation will focus on reducing the reliance on conventional reinforcing by introducing fiber reinforcing materials at the microscale, allowing the integration of tensile properties in structural design to improve durability and efficiency. New test methods will be presented to validate the potential benefits by identifying the controlling mechanisms of various fibers and textiles. Applications to address improved ductility-durability measures including correlation of ductility, crack width, stiffness degradation, and fatigue response with service loads will be presented. Several case studies will showcase the significant cost savings, and enhanced performance of these methods.

Product Spotlight - Chryso/GCP

Innovations in Low-carbon Cement Additives and Concrete Admixtures

Mike Stanzel, Technical Sales Representative, Cement Additives - North America, CHRYSO & GCP

Terry Harris, Senior Director Technical Services & Ductilcrete Slab Systems, CHRYSO & GCP

Portland limestone cement (PLC) and new blended cements using pozzolanic materials (fly ash, natural pozzolan and calcined clay (CC)), as well as ternary binders based on several supplementary cementitious materials (SCMs), are promising alternatives to conventional Portland cement. These options hold great potential for reducing the carbon footprint of concrete. Chryso has developed a new generation of cement and concrete strength enhancers that improve the viability and performance of PLC and blended cements in North America. These additives help overcome some of the challenges associated with these alternative cements, such as increased water demand, reduced strengths, and pack set issues.

Biochar-Cement Concrete: The Path to Carbon Neutrality and Strength Parity

Lori Tunstall, Assistant Professor, Colorado School of Mines

In the last decade, biochar has emerged as a promising partial cement replacement to significantly reduce the carbon footprint associated with concrete. This is because biochar is a carbon negative material, sequestering more than twice its weight in CO2. The more cement that can be replaced with biochar, the lower embodied carbon the concrete will have; however, most researchers have found that replacing the cement with more than 5 wt% of biochar results in decreased strength, which limits the environmental benefit. In contrast, through a study of 22 distinct biochars, we have found that up to 44 wt% of the cement can be replaced with biochar, resulting in comparable or improved mortar strength and the potential to completely offset the carbon footprint of the cement. Using advanced data processing techniques, we identify three key biochar characteristics that control strength development of biochar-cement mortars: available water sorption capacity, oxygen-to-carbon ratio, and soluble silicon.

SESSION 20: MAY 15, 2024

THE IMPORTANCE OF INNOVATION

De-Risking Lower-Carbon Concrete – The importance of innovation and the value proposition of leadership

Don Davies, Co-founder, Davies-Crooks Associates

Sara Neff, Head of Sustainability, Lendlease Americas

James Murray-Coleman, Director of Sustainability, Trammel Crow Company

Trammell Crow and Lendlease are industry leading developers, each with portfolios in the billions of dollars. They are placing a high value on future lower-carbon construction, and are championing a series of lower-carbon concrete pilot studies across the country. What is driving their decisions to innovate? What do they need from industry to support their goals? Moderated by Don Davies of Davies-Crooks Associates, a structural engineering veteran and leader of the Lower-Carbon Concrete Task Force, this panel will explore the motivations, risks, and value these efforts look to achieve.

Product Spotlight - AICrete

The Future of the Concrete Industry Using AI-Driven Solutions

Dr. Parham Aghdasi, Founder and CEO, AICRETE

This session will provide insights into the future of the concrete industry and how AICrete is leading the charge with AI-driven solutions. The presentation will dive into the heart of innovation with the newest features of AICreteOS. Attendees will experience first hand how this transformative operating system is reshaping the concrete production landscape, optimizing workflows, enhancing quality control, and revolutionizing every aspect of production. The session will highlight how strategic partnerships and integrations further amplify the power of AICreteOS and how collaborative efforts are driving innovation and delivering unparalleled value to the concrete industry.

Product Spotlight - Master Builders Solutions

Concrete Strength and Sustainability Redefined

Tyler Grissom, Product Manager, Master Builders Solutions

Nanoscale particulate-based admixture technologies are leading the way in concrete innovation. They effectively tackle the obstacles presented by supplementary cementitious materials (SCMs) and Type IL cements, paving the way for the creation of cost-effective and environmentally sustainable concrete mixtures with lower cement content.

SESSION 19: APRIL 17, 2024

ARCHITECTURE AND SUSTAINABILITY

Sustainable Concrete in the Building Industry: Opportunities and Challenges

Chris Flint Chatto, Principal, ZGF Architects LLP

Chris Chatto is a sustainability expert who found his way to architecture after a decade of work in environmental activism. As one of ZGF’s resident sustainable design experts, Chris develops simple, yet powerful tools to analyze data and understand how a project will impact and respond to the natural environment. This presentation demonstrates how ZGF used those tools along with collaborative approaches to sustainable design to ensure meaningful impact reductions, including embodied carbon of concrete.

Proactive CO2 reduction with TiO2-based surface treatments: Overview of methods, initial results & future perspectives in pavement applications

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Mirian Velay-Lizancos, Assistant Professor of Civil Engineering, Purdue University

It is known that TiO2 is a photocatalyst that can be used in construction materials applications as it provides them with photocatalytic properties, such as NOx removal. In addition to this property, our recent studies have shown the potential to increase the CO2 capture abilities of construction materials by adding nano-TiO2 into cementitious materials as part of the mix. These studies showed that these additions promoted the CO2 uptake to a certain level, depending on the samples' w/c and age, through carbonation acceleration, reducing the material's environmental footprint. However, the cost of nano-TiO2 and the potential increase in risk of corrosion if used in steel-reinforced concrete may reduce its applicability in the short term. Thus, our new study assesses the potential use of a TiO2-based surface treatment and its effect on CO2 concentrations and carbonation. These treatments present a cost-effective way to deliver TiO2 to pavements. However, their effect on the pavements differs from the effects of adding TiO2 into the mix since a surface treatment applied after the pavement has hardened will not modify the hydration process. Thus, we developed a new technique to assess the potential proactive effects of the surface treatment over the pavement's service life. Results showed that samples with the surface treatment reduced the concentration of CO2 to a greater extent than untreated samples. Furthermore, results also showed that, in this case, the reduction of CO2 concentration is not related to an increase in carbonation depth. Treated samples also showed self-cleaning ability. Thus, these treatments present a cost-effective way to deliver TiO2 to pavements, providing them with a long-lasting CO2 reduction ability.

Product Spotlight - Euclid Chemical

Decorative Concrete Innovations in Sustainability

Rich Cofoid, Sr. Marketing and Product Line Manager, Euclid Chemical

As sustainability and reduction in carbon emissions continue to drive innovations in concrete mix designs and construction, the decorative side of our business has not been left behind. In this presentation we will discuss some of the trends and evolutions in decorative concrete systems that combine aesthetics and sustainability.

2024 Concrete Innovations Award Winners