Engineering Commons^™

Thermoelectric Properties Of Cement Composite Analogues From First Principles Calculations, Esther Orisakwe, Conrad S.N. Johnston, Ruchita Jani, Xiaolo Liu, Lorenzo Stella, Jorge Kohanoff's, Niall Holmes Dr., Brian Norton, Ming Qu, Hongxi Yin, Kazuaki Yazawa

Articles

Buildings are responsible for a considerable fraction of the energy wasted globally every year, and as a result, excess carbon emissions. While heat is lost directly in colder months and climates, resulting in increased heating loads, in hot climates cooling and ventilation is required. One avenue towards improving the energy efficiency of buildings is to integrate thermoelectric devices and materials within the fabric of the building to exploit the temperature gradient between the inside and outside to do useful work. Cement-based materials are ubiquitous in modern buildings and present an interesting opportunity to be functionalized. We present a systematic investigation …

Comparing The Measured And Thermodynamically Predicted Afm Phases In A Hydrating Cement, Niall Holmes Dr., Mark Russell, Geoff Davis, Mark Tyrer

Articles

In hydrating Portland cements, more than one of the AFm family of calcium aluminates may exist. Depending on the amount of carbonate and sulfate present in the cement, the most common phase to precipitate is monosulfate, monocarbonate and/or hemicarbonate. It has been reported in the literature that hemicarbonate often appears in measurements such as XRD but not predicted to form/equilibrate in thermodynamic models. With the ongoing use of commercial cements such as CEM I and CEM II containing more and more limestone, it is important to understand which hydrate solids physically precipitate and numerically predict over time. Using 27 cement …

Employing Discrete Solid Phases To Represent C-S-H Solid Solutions In The Cemdata07 Thermodynamic Database To Model Cement Hydration Using The Phreeqc Geochemical Software, Niall Holmes Dr., Mark Tyrer, Denis Kelliher

Articles

This paper presents a cement hydration model over time using the cemdata07 thermodynamic database and a series of derived discrete solid phases (DSPs) to represent calcium silicate hydrate (C-S-H) as a binary solid solution with two end-members. C-S-H in cement is amorphous and poorly crystalline with a range of molar Ca/Si ratios from 0.6 to 1.7. It displays strongly incongruent dissolution behaviour, where the release of calcium into solution is several orders of magnitude greater than silicon. It is, therefore, important that any cement hydration model provides a credible account of this behaviour. C-S-H has been described in the cemdata07 …

Review Of Fly-Ash As A Supplementary Cementitious Material, Nikki Shaji, Niall Holmes Dr., Mark Tyrer

Conference papers

This paper presents a review of fly-ash as a Supplementary Cementitious Material (SCM) in concrete in terms of its effects on hydration and durability. The climate change agenda has focused the cement and concrete industry on using low embodied CO2 materials and much effort has been made on incorporating industrial by-products into cement as SCMs. With worldwide cement production (circa 4 billion tonnes) currently accounting for approximately 8% of global CO2 emissions and 7% of industry energy use, the use of suitable SCMs to partially replace cement in concrete is extremely important. However, while coal-fired power stations are in the …

Deriving Discrete Solid Phases From Csh-3t And Cshq End-Members To Model Cement Hydration In Phreeqc, Niall Holmes Dr., Colin Walker, Mark Tyrer, Denis Kelliher

Conference papers

This paper presents a cement hydration model over time using the CEMDATA thermodynamic database and a series of discrete solid phases (DSP) to represent calcium silicate hydrate (C-S-H) as a ternary (CSH-3T) and quaternary (CSHQ) solid solution. C-S-H in cement is amorphous and poorly crystalline with a range of molar Ca/Si ratios = 0.6-1.7 and displays strongly incongruent dissolution behaviour where the release of calcium into solution is several orders of magnitude greater than silicon. It is therefore important that any cement hydration model provides a credible account of this behaviour. C-S-H has been described in the CEMDATA thermodynamic database …

Using Metal-Organic Frameworks (Mof) To Reduce The Carbon Footprint Of Concrete, Mona Ibrahim El-Hallak

Theses

The production of concrete by the construction industry has a massive impact on the environment. The process of manufacturing its main component, cement, releases a considerable amount of anthropogenic carbon dioxide. This thesis is concerned with the production of sustainable and eco-friendly concrete that integrates metal-organic frameworks (MOF) to capture and offset the CO₂ emissions emitted during the production of cement. The main objective is to synthesize a MOF capable of capturing CO₂ in concrete through accelerated carbonation curing and to assess its impact on concrete performance. Different parameters were examined, including the MOF content, initial curing duration, …

The Impact Of Material And Environmental Properties On The Ettringite - Metaettringite Thermochemical Reaction, Aaron Strand

Dissertations

The use of energy is an essential need for people, with demand constantly increasing due to an increasing population and an increase in living and comfort standards. Since 1965, world energy consumption has quadrupled. During peak utilization, the strain on the grid infrastructure can be immense. As energy demand fluctuates during different times of the day and year, the energy production needs to scale accordingly This creates inefficiencies within the system such as over building generation capacity or losses from start up or ramping up production. This can be alleviated through load leveling where excess energy generated during low demand …

Application Of Biochar As Beneficial Additive In Concrete, Temirlan Barissov

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Biochar is a high-carbon solid material produced via thermal decomposition of organic biomass in a low-oxygen environment. Characterized with high water retention properties and high alkalinity, biochar is generally used for soil amendment and fertilization purposes. This study is intended to explore the feasibility of using biochar as a beneficial additive of the most used manmade material, concrete. Literature review revealed several studies where biochar was successfully implemented as an additive in concrete. The beneficial influence of biochar on the mechanical characteristics of concrete is based on nucleation and densification effects. However, the internal microstructure, porosity and chemical composition of …

Hydration, Shrinkage, Cracking, And Mechanical Properties Of Cementitious Materials With Lignocellulosic Biomass Wastes., Aofei Guo

Electronic Theses and Dissertations

The disposal of lignocellulosic biomass wastes imposes a huge economic and environmental burden on this society. Recycling lignocellulosic biomass wastes and applying them to cementitious materials provides a sustainable and value-added way for both agriculture and concrete industries. To comprehensively identify the effect of lignocellulosic biomass wastes at different scales on cementitious materials, the hydration, shrinkage, cracking, and mechanical properties of cementitious materials with lignocellulosic biomass wastes were studied. Given the three different forms (powders, chips, and fibers) of lignocellulosic biomass wastes in this study, the research was implemented in three stages. In the first stage, hemp powders were collected …

Effects Of Accelerated Carbonation Curing On Co2 Sequestration And On The Compressive Strength Of Concrete Masonry Units, Barry Gilroy, Leon Black, David Thompson, Ronan Hogan, Niall Holmes

Conference papers

The global consumption of Portland cement has risen to over 4 billion tonnes per annum. Its manufacture is energy and carbon intensive and approximately 900 kg of CO2 is emitted into the atmosphere for each tonne of Portland cement produced. The International Energy Agency (IEA) roadmap sets out a goal to reduce emissions due to cement production to 18 % below 2006 levels by 2050. Concrete has the potential to re-absorb CO2 by the process of carbonation, where it reacts with CaO in the concrete to form calcium carbonate. Accelerated carbonation curing (ACC) is a technique for curing fresh concrete …

Flexural Load Capacity Of Heat-Treated Concrete Mixed With Recycled Glass Aggregate And Glass Pozzolan, Enrique Gonzalez Tapia

Civil Engineering Theses

This research focuses on determining the effects of adding glass aggregate and glass pozzolan to concrete that has been exposed to high temperatures. Previous work, based on finding the recommended proportions of recycled components for optimum results, was done to analyze the effects of adding recycled glass components to concrete. Based on those studies, a replacement ratio of 30% glass aggregates and 20% glass pozzolan was used in this project. The compressive strength of concrete has been extensively studied and has been shown to increase in strength when glass components are used in their correct proportions. Less research has been …

Low-Grade Kaolin Clay Natural Resource For Use As A Supplementary Cementitious Material In Structural Concrete Elements, Brandon X. Lorentz

USF Tampa Graduate Theses and Dissertations

At the turn of the century, low-grade kaolin clay (LGK) was presented as a widely available and potential natural resource of supplementary cementitious materials (SCM) for producing high performance concretes. In using LGK as an SCM, clinker production is reduced, aiding environmental concerns with associated CO2 emissions. These types of clays have very heterogeneous mineralogy and microstructural characteristics, causing unique influences on concrete structural and flow performance, although these influences are not well understood. This research studies LGK natural to the state of Florida and assesses their potential use as high performance SCM.

Ten kaolin clays were obtained through a …

Development Of A Mix Design Adjustment Method For Fiber Reinforced Concrete And Super High Performance Concrete Based On Excess Paste, Joe Malloy

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The main objective of this study was to develop a mix design adjustment method for Fiber Reinforced Concrete (FRC) that would maintain appropriate workability while improving hardened concrete performance. A literature review was conducted to examine existing methods for adjusting mix designs to account for fiber introduction. It was found that while increasing fine aggregate and cement paste content can make up for lost workability with the addition of fibers, no rational mix design adjustment method is available. Reference mix designs from the Nevada Department of Transportation and the Nebraska Department of Transportation were used, and this study focused on …

Influence Of Exposure Environments On The Durability Of Slag-Blended Cements, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black

International Conference on Durability of Concrete Structures

Both chlorides and sulphates combine in seawater to affect the durability of reinforced concrete structures located in marine environments. This paper presents the results of an experimental study on slag blended cement systems, cured for 7 days, before exposure to a combined solution of sodium chloride (30 g/L) and sodium sulphate (3 g/L). Two slags of different chemical compositions, designated as slags 1 and 2 were respectively blended with Portland cement CEM I 52.5R at 30 and 70 wt.% replacement levels. Mechanical tests on mortar samples were complemented by microstructural examination and chemical characterisation on paste samples, all using a …

Performance Of Concrete Made With A Calcined Clay – Limestone-Portland Cement Exposed To Natural Conditions, Fernando Martirena, Ernesto Díaz, Dayran Rocha, Hamed Maraghechi, Karen Louise Scrivener

International Conference on Durability of Concrete Structures

This work presents the results of an investigation carried out to assess durability of concrete made with a calcined clay- limestone-Portland cement with 47% of clinker, hereafter named LC3, produced during an industrial trial in 2013. LC3 was used to cast concrete blocks and later expose them at a natural location at the northern coast of Cuba. Reference concrete was cast with Cuban Portland cement having 88% of clinker. Throughout three years (2015, 2016, 2017) concrete cores were systematically taken and the specimens were subjected to a testing program that included Formation factor, chloride profiling, surface resistivity, air permeability and …

Effects Of Temperature And Curing Duration On The Stability Of Slag Cements In Combined Chloride-Sulphate Environments, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black

International Conference on Durability of Concrete Structures

This experimental study investigates the effects of temperature and curing duration on the stability of slag blended cement systems exposed at 20 °C and 38 °C to combined sodium chloride (30 g/L) – sodium sulphate (3 g/L) solutions. Two slags, designated as slag 1 and 2, having CaO/SiO₂ ratios of 1.05 and 0.94, were respectively blended with Portland cement CEM I 52.5R at 30 wt.% replacement level. Mortar prisms and cubes with w/b ratio of 0.5 and binder/aggregate ratio of 1:3 were then prepared for length and mass changes. The samples were cured in lime water for either 7 …

Modelling The Addition Of Limestone In Cement Using Hydcem, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

Hydration models can aid in the prediction, understanding and description of hydration behaviour over time as the move towards more sustainable cements continues.

HYDCEM is a new model to predict the phase assemblage, degree of hydration and heat release over time for cements undergoing hydration for any w/c ratio and curing temperatures up to 450C. HYDCEM, written in MATLAB, complements more sophisticated thermodynamic models by predicting these properties over time using user-friendly inputs within one code. A number of functions and methods based on up to date cement hydration behaviour from the literature are hard-wired into the code along with …

Hydcem: A New Cement Hydration Model, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

Hydration models are useful to predict, understand and describe the behaviour of different cementitious-based systems. They are indispensable for undertaking long-term performance and service life predictions for existing and new products for generating quantitative data in the move towards more sustainable cements while optimising natural resources. One such application is the development of cement-based thermoelectric applications.

HYDCEM is a new model to predict the phase assemblage, degree of hydration, heat release and changes in pore solution chemistry over time for cements undergoing hydration for any w/c ratio and curing temperatures up to 450C. HYDCEM, written in MATLAB, is aimed at …

Potential Value-Added Utilization Of Wood Ash In Construction Materials, Naveen Saladi

Electronic Theses and Dissertations

Wood ash is a byproduct from biomass power plants. Most of the wood ash is currently being disposed of as landfilling material that causes severe economic and environmental concerns. This project focuses on the feasibility of using this wood ash in construction materials. Wood ash was found to contain varieties of mineral phases including calcium carbonate, calcium aluminate, and quartz. Based on the chemical composition, the efficacy of wood ash (i) as supplementary cementitious materials (SCM), (ii) in the controlled low strength materials (CLSM) production and (iii) Portland cement production was evaluated.

Wood ash with adequate pozzolanic properties can be …

Effects On Strength And Corrosive Characteristics Of Hardened Cement Paste Using Rice Husk And Sugarcane Bagasse, Travis D. Garrett

Master's Theses

Cement is one of the most used building materials in the world. The production of ordinary Portland cement contributes to the release of harmful greenhouse gasses. In an effort to reduce these emissions, different materials are being evaluated for their use as partial replacements for ordinary Portland cement. Rice husk and sugarcane bagasse are agricultural waste products and large amounts of these are currently landfilled, making them inexpensive and available. When combusted at high temperatures they form rice husk ash and sugarcane bagasse ash that have pozzolanic characteristics. The high silicon dioxide in these products makes them good options to …

Adhesion Of Bituminous And Cementitious Materials Using Particle-Probe Scanning Force Microscopy, Yujie Li

Graduate College Dissertations and Theses

As the most important materials in civil engineering, bituminous and cementitious materials have been used widely in pavements and constructions for many years. Accurate determination of adhesion is important to the bonding properties of bituminous and cementitious materials. In this work, we presented a novel approach to measure the adhesion between binders and aggregate mineral particles at microscopic scale.

Particle probe scanning force microscopes (SFM) were used to study the adhesion between mineral microspheres representing the primary aggregate constituents (Al2O3, SiO2 and CaCO3) and various control (PG 64-22 and PG 58-22) and modified binders. Results showed that these modified SFM …

Effect Of Cement Content On Concrete Performance, Caleb Joshua Lebow

Graduate Theses and Dissertations

Of all the traditional concrete materials, portland cement has the greatest impact on mixture cost and the environment. Cement is in many ways the glue holding concrete together (Weiss, 1999), and as such, it plays a major role in fresh and hardened concrete properties. Without the proper range of cement in the mixture, low strength development or excessive shrinkage may occur leading to premature deterioration. The Arkansas Department of Transportation (ARDOT) recognizes two types of concrete for use in bridge construction, Class S and Class S(AE). This paper focuses on the findings from testing of Class S(AE) concrete, short for …

Coir Fiber Reinforced Concrete, Jose De La Serna, Moses Karakouzian

AANAPISI Poster Presentations

This poster exhibits the testing and research done on general Portland Cement Concrete with the addition of coir (coconut) fibers as reinforcement. Using the fundamental constituents of cement (water, cement, fine and coarse aggregate) and processed coir fiber, concrete specimens were batched to test for compressive and flexural strengths (per appropriate ASTM standards). Cylindrical and rectangular beam specimens were subjected to loadings until failure occurred. The capacity and modes of failures of the specimens were observed. It was determined that:

• The addition of processed coir fibers decreases the overall strength of general Portland Cement Concrete. • The tested concrete’s …

Introducing A New Cement Hydration And Microstructure Model, Niall Holmes, Anselm Griffin, Bernard Enright, Denis Keliher

Conference papers

This paper presents a new cement hydration model to predict the microstructure evolution of hydrating tricalcium silicate (C3S). The model is written in MATLAB and employs the continuum approach and integrated particle kinetic relationships to show the change in C3S and the growth of Calcium Silicate Hydrate (C-S-H) and Calcium Hydroxide (CH) in the pore space over time.

Cement hydration is a highly complex process. While hydration models should never completely remove experimental analysis, they are an aid to better understand cement hydration and microstructure development by providing a method to analyse a large number of pastes with different cementitious …

Preliminary Investigation Of Tensile Strength And Impact Characterization Of Cementitious Composite Incorporating Carbon Nanotubes, Robabeh Jazaei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cement has been largely used in the construction industry, specifically as a matrix for concrete. Recently, a new generation of cement-based composite that greatly increases mechanical properties is replacing conventional concrete. With periodic advances in the field, researchers considered particles with high-aspect ratios such as Carbon Nanotubes (CNTs) to reinforce cement matrices. Although there is not much literature to draw upon in research, some research on improving the tensile strength of cementitious composite incorporating with CNTs does exist. However, there had been no evidence of investigation into impact strength until this study.

Most papers presented examined the effect of multi-walled …

Performance Of Lime- And Cement- Based Treatments Of Sulfate-Rich Soil Via Rc Testing, Azadeh Asghariastaneh

Civil Engineering Theses

Chemical treatment of expansive sulfate-rich soils, particularly lime- and cement-based methods, had been rather popular due to their relatively low cost and ready availability. However, over the last few decades, extensively documented pavement failures, mainly caused by excessive heaving and/or shrinkage of lime- and cement-treated subgrades with moderate-to-high sulfate content, have led to thorough investigations to assess the actual feasibility and effectiveness of calcium based stabilizers in sulfate-rich soils. Studies have concluded, with solid experimental evidence, that the calcium present in the chemical stabilizers react with the sulfate and alumina of the treated soil to form Ettringite, an expansive mineral …

High Early-Age Strength Concrete For Rapid Repair, Matthew O. Maler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The aim of this research was to identify High Early-Age Strength (HES) concrete batch designs, and evaluate their suitability for use in the rapid repair of highways and bridge decks. To this end, two criteria needed to be met; a minimum compressive strength of 20.68 MPa (3000 psi) in no later than 12 hours, and a drying shrinkage of less than 0.06 % at 28 days after curing. The evaluations included both air-entrained, and non-air-entrained concretes.

The cement types chosen for this study included Type III and Type V Portland cement and “Rapid Set” − a Calcium Sulfoaluminate (CSA) cement. …

Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton

Articles

The development of a battery using different cement-based electrolytes to provide a low but potentially sustainable source of electricity is described. The current, voltage, and lifespan of batteries produced using different electrolyte additives, copper plate cathodes, and (usually) aluminium plate anodes were compared to identify the optimum design, components, and proportions to increase power output and longevity. Parameters examined include water/cement ratio, anode to cathode surface area ratio, electrode material, electrode spacing, and the effect of sand, aggregate, salts, carbon black, silica fume, and sodium silicate on the electrolyte. The results indicate that the greatest and longest lasting power can …

Design Of Magnesium Phosphate Cement Based Composite For High Performance Bipolar Plate Of Fuel Cells, Wenbin Hao, Hongyan Ma, Zeyu Lu, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on a magnesium phosphate cement (MPC) based composite as the construction material for high performance bipolar plates of fuel cells. MPC with partial replacement of fly ash was employed as the binding matrix. Some carbon-based materials, such as graphite, carbon black, carbon fiber, and multi-walled carbon nanotubes were used to construct the conductive phase. A simple hot-press process was applied to produce the composite. The formula and the structure of the composite was modified and adjusted to optimize the properties of the composite to meet the US DOE 2015 technical targets, including …

Evaluating A New Cem Iii/A Cement For Concretes Exposed To Harsh Acid Rich Environments, David Thompson, Niall Holmes, John Reddy

Conference papers

The Irish Annex to the European specification, performance, production and conformity of concrete, IS EN 206, recommends CEM III/B cement for acid rich environments containing between 66 to 80% GGBS. However, BS 8500, the UK annex to EN 206 and the British Research Establishment (BRE) Special Digest 1, recommends CEM III/A cement with a GGBS range of 36-65%. This project investigated the performance of a new CEM III/A cement produced by Ecocem Ireland in concretes exposed to such environments using an extensive suite of laboratory tests.

In Ireland, up to €5.8bn will be invested to provide fresh drinking water and …