Lionel Lemay PE, SE, LEED AP

Mr. Lemay is Sr. Vice President, Sustainability and Technical Resources for the National Ready Mixed Concrete Association (NRMCA). He manages programs that assist concrete producers, contractors, and design professionals transform concrete manufacturing and construction to improve overall sustainability of the concrete industry. He manages programs to educate concrete industry professionals, engineers and architects on the proper use and design of concrete for buildings, parking areas, roadways, and other applications.

Mr. Lemay has written numerous articles on concrete design and construction and is co-author of the McGraw-Hill book Insulating Concrete Forms for Residential Design and Construction and contributor for FEMA 320 Taking Shelter From the Storm: Building a Safe Room For Your Home or Small Business. He is a Registered Professional Engineer and Structural Engineer in the State of Illinois. He is also a LEED Accredited Professional. Mr. Lemay holds a bachelors and masters degree in civil engineering and applied mechanics from McGill University in Montreal, Canada.

New Radical Materials and Resources Reporting Criteria in LEED v4

Lionel Lemay

With the proliferation of eco-labels and green certifications worldwide, it can be confusing determining a product’s sustainable attributes. Over the past 10 years the LEED rating system developed by the US Green Building Council has steadily transformed the marketplace and is set to do so again with the newly released LEED v4. The new version has radically overhauled of the Materials and Resources (MR) credits. The revamped MR credits, now called Building Product Disclosure And Optimization, will create opportunities for manufacturers who take the path to transparency through Environmental Product Declarations (EPDs), Corporate Social Responsibility (CSR) Reports, and Health Product Declarations (HPDs).  Well established in other industries, these metrics are starting to appear in the construction industry as common methodologies for assessing the sustainable performance of a product, process or organization.  This presentation will offer an overview of EPDs, CSRs, and HPDs and what they mean for the concrete industry.

Colin Lobo Ph.D., P.E.,

Dr. Lobo is Sr. Vice President, Engineering for the National Ready Mixed Concrete Association (NRMCA). He manages research, education, certification programs and represents the ready mixed concrete industry in various codes and standards committees. He is a member of ACI Committees 301 on specifications and 318 on the building code for structural concrete. He serves on several committees of ASTM that develops standards for concrete and concrete materials. He is responsible for several industry education and certification program, including the NRMCA certification program for concrete production facilities.

Dr. Lobo has written numerous articles and industry publications on concrete technology. He is a co-author of ASTM Manual 49 Understanding ASTM C94 – Specification for Ready Mixed Concrete. Dr. Lobo holds a Ph.D. in civil engineering from Purdue University in the US. He is a licensed engineer in the state of Maryland, USA.

Specifying Durability Requirements for Concrete – Is There a Better Way?

Colin Lobo

Globally, there is a wide range of methods of establishing specification requirements to address durability of concrete. Most codes and standards establish a process of assigning a durability exposure classification for concrete members depending on the anticipated exposure to environmental conditions in service. These then dictate the requirements for concrete mixtures. In most cases, reliance is on prescriptive requirements like water-cementitious materials ratio or minimum quantities of cementitious materials. Is there a better way to state requirements for concrete in terms of performance-based test and associated test criteria that can more reliably achieve the characteristics needed? The presentation will discuss the deficiencies of current ways and suggest some performance-based alternatives that better assure durable concrete, promote innovative technology and support sustainability initiatives.  

Hilal El-Hassan, PhD

Dr. Hilal El-Hassan is an Assistant Professor of Civil Engineering at the American University in Dubai, UAE. His teachings span the areas of structural analysis, concrete design, and foundation design. Prior to joining AUD, he was a research associate at McGill University in Montreal, Canada. Dr. El-Hassan finished his PhD degree in civil engineering majoring in the structural and materials departments under the supervision of Professor Yixin Shao. His research interests comprise of investigating the effect of early-age carbonation on concrete products including concrete masonry units, concrete pipes, and concrete pavement. Dr. El-Hassan's work on concrete masonry units examined the ability to permanently sequester carbon dioxide gas in the form of the thermodynamically stable calcium carbonate, while thriving to maximize the uptake in order to reduce global carbon dioxide emission.

Dr. El-Hassan received his Bachelors and Masters of Science degrees with honors alongside an excellence award for engineering students from University of Balamand, Lebanon. He also received a prestigious MEDA (McGill Engineering Doctoral Award) for his exceptional performance before and during his doctoral degree. He has several publications in civil engineering journals including ACI and ASCE material journals discussing the different aspects of concrete carbonation and its effect on concrete microstructure.

Carbonation Curing of Sustainable Green Concrete Blocks with Portland Limestone Cement

Hilal El-Hassan, Yixin Shao

Concrete blocks have been widely utilized as load-bearing and non-load-bearing partition walls in construction. Currently, the UAE annual consumption of concrete blocks is nearly 400 million units projected to increase between 5 and 10% yearly. These concrete blocks are made of calcium silicate cement, porous in nature, and mass produced. However, the production of the cement poses several sustainability issues that require adjustment, mainly the emission of CO₂ gas during production.

While Ordinary Portland Cement is the most commonly used conventional cement, Portland Limestone Cement is slowly getting accepted as an environment friendly and economically competitive alternative. Based on CSA A3000-08, limestone addition of up to 5% is allowed with no label. Therefore, OPC used nowadays is actually low limestone cement (3-5%) in comparison to high limestone cement with 13-15% limestone and clearly labeled as PLC. The use of limestone is one of a few important sustainable developments by the cement industry. It is vital to understand the differences of using either cement in the carbonation curing process of concrete masonry units by evaluating their performance and analyzing the microstructure changes.

Carbonation curing is a 3-step process that incorporates 18 hours of initial air curing in a controlled environment, 4 hours of carbonation curing in a sealed chamber at 0.1 MPa, and subsequent hydration of up to 28 days. Water loss during the procedure is compensated for utilizing a spraying mechanism. The resultant sprayed concrete is directly compared to the non-sprayed sample and to a hydrated counterpart. In order to evaluate the effect of carbonation on both kinds of concretes, carbon uptake using five different estimation methods is compared. With reference to the hydrated concrete, the carbonated samples are also assessed based on compressive strength and morphological changes using scanning electron microscopy (SEM).

The carbon uptake based on cement mass reached 24% in carbonated OPC concrete, while it did not exceed 20% in the PLC counterpart. It should be noted that with 3-4% carbon content in as-received OPC compared to 14-15% in as-received PLC, the comparison should be based on pure cement content by eliminating the added limestone from the calculation of carbon uptake. Such a distinction leads to a carbon uptake of approximately 22% for both concretes. The effect of carbonation curing on compressive strength is investigated after 1 and 28 days. In both curing conditions, OPC concrete experienced a 5-10% increase in 1-day strength over PLC, and up to 15% after 28 days subsequent hydration. With 15% cement replacement with limestone, less hydration and carbonation reactants are present in PLC concrete, resulting in lower compressive strength.

The concrete morphology investigated employing SEM showed distinctive changes due to carbonation in each kind of concrete. While carbonated OPC showed a grainy, blurry microstructure, its PLC counterpart presented crystal-like shapes protruding from a granular background. On the other hand, both concretes showed similar morphology when they underwent hydration curing.

Annual cement production in the UAE is approximately 25 million tonnes and its corresponding CO₂ emission is about 20 million tonnes. If all blocks produced annually are processed by CO₂ curing for accelerated hydration and carbon storage, the block production could consume 0.2 million tonnes of CO₂ per year based on an uptake of 24%. The corresponding emission reduction in cement industry can reach 1.0% by concrete block production alone. The calculations performed beforehand are applicable for both OPC and PLC concrete blocks. The current investigation shows that carbonation can be used on other precast structural components to further reduce carbon emissions whilst providing a permanent carbon sequestration process.

Dr. Giorgio Ferrari

Dr. Giorgio Ferrari is senior researcher at Mapei S.p.A., Milan (Italy). He graduated in Chemistry at the University of Padua in 1977. He is author of more than 50 scientific publications and presentations at international conferences in the field of concrete additives and environmental issues and he is author of several international patents and two books. Fields of interest include research and development of new concrete additives, modeling of cement hydration and new sustainable construction materials and environmental protection.

New Sustainable Technology for Recover Returned Concrete

Giorgio Ferrari

Globally, more than 100 million cubic meters/year of ready mixed concrete are not placed and are returned to the concrete mixing plant. Only a fraction of returned concrete can be recycled in new concrete batches and the residual amount must be treated, representing a heavy burden for the ready-mixed plant. In the present paper, a new sustainable technology to recycle returned concrete is presented, which uses specific, non-toxic, additives added directly into the drum of the truck mixer. After few minutes of mixing, the additives transform the returned concrete into granular materials that can be reused as aggregates for the production of new concrete, without producing any waste. With the new method, quarries’ exploiting is reduced and natural resources are preserved. Furthermore, the new technology allows a reduction of the overall costs both for waste disposal and for aggregates supplying. Therefore, the new technology has important environmental, social and economical issues for sustainability.

Zaid Ghouleh, B.Eng., M.Eng., Ph.D. (cand.)

Obtaining a bachelor’s degree in Materials Engineering from McGill University in 2005, Mr. Ghouleh resumed academic research after accruing a few years of industrial experience in metallurgy-related, specialty engineering fields. He attained a master’s degree under the same department in 2009, with a major focus on waste remediation and recycling. He later enrolled in the department of Civil Engineering to complete a Ph.D degree. His doctorate dissertation involves exploring innovative methodologies that promote sustainable building practices, ones to contribute to resource conservation and emission mitigation in the construction industry. His relevant areas of interest include waste valorization, high temperature processing and thermodynamic simulations, accelerated carbonation, mineral sequestration, carbon capture and storage (CCS), and waste-derived concrete products.

Valorization of Industrial Wastes for Building Applications with the Added Benefit of Carbon Sequestration

Zaid GHOULEH, Yixin SHAO, Roderick I.L. Guthrie

With the world’s current high output of industrial goods, hundreds of millions of tons of manufacturing by-products end up amassing in landfills each year. Steel-slag is not recycled to any significant degree, and even banned as a construction material in certain countries, such as Canada. This limitation is mainly attributed to a lack in performance criteria permitting its economic and safe reuse. Moreover, the steel industry is a major contributor to anthropogenic CO₂, and is subject to increasingly harsher regulatory codes that mandate heavier emission reductions. This project introduces a value-adding carbonation treatment that substantially enhances the waste slag’s physical properties and, hence, its recyclable potential, while also presenting the added benefit of sequestering CO₂. The end-use of the valorized slag as an aggregate replacement in concrete is explored. Considering that concrete is the world’s most used construction material (> 9 billion tons per year), this project presents a sustainable building practice that fits within holistic environmental initiatives related to waste recycling, carbon mitigation, and resource conservation. In terms of practicality, an 8” concrete masonry block prepared in the prescribed manner will potentially sequester up to 2 kg of CO₂. The project ultimately seeks to demonstrate the possibility of implementing a closed loop system, for relevant industries, whereby waste streams and CO₂ can be locally consumed at point source.

Mohammad Mahdi Khodaparast

Concrete researcher and CEO of SGC (Sustainable Green Concrete) Engineering Company. He is a Concrete Expert and project manager of TUMC (Technical Unit of Materials & Concrete) at Power & Water University of Technology, Iran. He has a B.Sc in civil engineering – hydraulic structures. He is a Ph.D student at the Coventry University, on Sulfate Resistance of Alkali Activated Natural Pozzolan Concrete. Mohammad has conducted several researches in concrete durability test methods. He has presented papers in international conferences on different subjects, Geopolymer concrete, Pre-stressed concrete bridges construction, Influence of nano silica in concrete permeability. Mohammad published several papers in Concrete Technology Journal of ACI.

An Innovative Experimental Method to Determine Water Penetration Depth in Concrete (Durability Estimation & Evaluation Test Method)

Farshad Vazinram, Mohammad Mahdi Khodaparast

Nowadays, concrete plays an outstanding role in construction industry and variety of engineering
infrastructures such as bridges, dams, jetties, piers and channels which are made of concrete.
Since from one hand, these huge and critical concrete structures in which some cases are of
lifelines of a country are of great importance and on the other hand, the necessity of conservation
and durability of these structures is inevitable, the importance of concrete durability will become
vividly apparent. One of the factors that can deteriorate the reinforced concrete condition by
corrosion and cause cracking in severe cold weather, has turned out to be water penetration into
concrete. With this respect, one of the practical and efficient ways ever used to countermeasure
this situation is to use water proof additives and admixtures in concrete mix in order to reduce
water and waste water absorption and penetration into concrete.

In this investigation, PN gel, PN liquid and PN liquid along with micro silica powder as waterproofing additives and admixtures, were used in separate mix designs to make specimens and then these specimens and the witness were tested by two methods in order to determine water absorption and penetration depth in concrete. In one of these two methods, water absorption percentage was just determined and in the other one which was more accurate and was implemented by triaxial apparatus, both water absorption and penetration depth in the specimens were investigated. Finally, the tables and diagrams for gained results concerning specimens containing PN additives and witness were prepared and compared. The results showed about more than 50% improvement in water penetration reduction.

Diego Felipe Velandia, MSc.

Civil Engineer from Universidad Militar Nueva Granada, MEng in Structural Engineering from Universidad de los Andes, MSc in Structural Engineering and Materials from Cardiff University. Nowadays, PhD student from the University of Sheffield in UK. Different academic awards such as the Presidential Academic Award from the US Presidency, the South Wales Institute of Engineers Educational Trust, scholarships and registration with honors. Author of one book, conferences and journal papers. Research experience in different companies such as British Petroleum and Corus Group Steel Producer in UK. Now Technical Development Chief Engineer in Concretos Argos Colombia.

Characterization of High Percentages of Fly Ash With Sodium Sulfate as Activator for Ultra Optimum Green Concretes

D. F. Velandia, C. Lynsdale, F. Ramirez, J. Provis, E. Arteta, G. Hermida, Ana Gomez 

Concretes with high volume fly ash and activators are an alternative to reduce CO₂ emissions. According to the results of this study, the amorphous content of fly ash was the most influencing factor for the compressive strength for mixes with low fly ash content (20%) and without any activator. By improving fly ash fineness its composition was affected; the amorphous, silica and LOI content were different for each fineness. The compressive strength of mortar samples was improved when the amorphous content increased; in some cases even when the particle size and the LOI content decreased, the compressive strength decreased. At some point fly ashes would not need a mechanical treatment depending on the initial amorphous content. For mixes with sodium sulfate, its effect over mixes with TP fly ash and FB fly ash was significant at initial ages; the amount of ettringite and portlandite consumption was reflected on the compressive strength evolution. In the other hand, sodium sulfate did not have the same effect on TG FA and TA FA; the amount of ettringite and portlandite consumptions was not significant as it was with the first two fly ashes. In the bound water levels, it always increased significantly for TP FA and FB FA. Although the bound water for TA FA and TG FA increased, it occurred in a small proportion. The main difference between these fly ashes was the high amount of Fe₂O₃ for the last two. 

Kryton Demonstration: Concrete Waterproofing

As the inventors of the crystalline waterproofing admixture Kryton takes the risk out of concrete waterproofing, see for your own eyes how our admixture completely waterproofs a concrete tank constructed using Cemex concrete by Ali & Sons. For the past 40 years Kryton has been waterproofing concrete with the most COMPLETE system, see our complete system in action: watch Kryton perform a crack repair and demonstrate our Krystol Waterstop System. Kryton products have undergone more testing and received more approvals than any other during our demonstration we will review or newest certificate from the Dubai Municipality.

Mapei Demonstration: Recovering Returned Concrete

A full scale demonstration of the new technology will be given. Two cubic meters of returned concrete in a truck mixer are treated with a new additive and transformed, in few minutes, into a granular material that is discharged from the truck mixer and can be reused, after curing, as aggregates for the production of new concrete. No liquid and solid wastes are produced by this new sustainable technology.