Engineering Commons^™

On The Use Of Machine Learning And Data-Transformation Methods To Predict Hydration Kinetics And Strength Of Alkali-Activated Mine Tailings-Based Binders, Sahil Surehali, Taihao Han, Jie Huang, Aditya Kumar, Narayanan Neithalath

Electrical and Computer Engineering Faculty Research & Creative Works

The escalating production of mine tailings (MT), a byproduct of the mining industry, constitutes significant environmental and health hazards, thereby requiring a cost-effective and sustainable solution for its disposal or reuse. This study proposes the use of MT as the primary ingredient (≥70%mass) in binders for construction applications, thereby ensuring their efficient upcycling as well as drastic reduction of environmental impacts associated with the use of ordinary Portland cement (OPC). The early-age hydration kinetics and compressive strength of MT-based binders are evaluated with an emphasis on elucidating the influence of alkali activation parameters and the amount of slag or cement …

Understanding Roles And Evaluating Reactivity Of Fly Ashes In Calcium Aluminate Binders, Sai Akshay Ponduru, Taihao Han, Jie Huang, Narayanan Neithalath, Gaurav Sant, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Calcium aluminate cement (CAC) is an alternative to Portland cement, valued for its superior early strength and thermal resistance. Partially replacing CAC with Fly ash (FA) can reduce carbon footprint and production costs of CAC, producing sustainable cementitious binders. This research investigates on various properties (i.e., hydration kinetics; phase assemblage evolution; compressive strength) of [CAC + FA] binders. Using 13 distinct FAs, up to 50% of CAC was substituted. The study measures hydration kinetics, compressive strength, and employs the number of constraints to estimate FA reactivity. Advanced quantitative analysis draws links between hydration kinetics and compressive strength and elucidate the …

Hempcrete Curtain Walls, Anh Bui

2024 Awards for Excellence in Student Research and Creative Activity - Documents

This research aims to scrutinize the performance, durability, and viability of hempcrete in curtain wall applications—an exploration critical to advancing sustainable construction practices. Comprising hemp hurds and lime binders, hempcrete stands as an emerging sustainable building material with promising ecological benefits. Despite its potential, there exists a notable research gap concerning its application in curtain walls, which demand rigorous structural and weatherproofing standards. The primary objective is to subject full-scale hempcrete curtain wall assemblies to ASTM standard test methods, comparing their performance with conventional materials like stone and glass. The research hypothesis posits that hempcrete will exhibit satisfactory strength, fire …

Assessment Of The Mechanical And Durability Characteristics Of Bio-Mineralized Bacillus Subtilis Self-Healing Concrete Blended With Hydrated Lime And Brick Powder, Mohd Abu Bakr, Birendra Kumar Singh, Ahmed Farouk Deifalla, Shatrudhan Pandey, Ahmed Hussain, Sahir Sultan Alvi, S.M. Mozammil Hasnain

Civil Engineering Faculty Publications and Presentations

Highlights

• The present paper studied the effect of biomineralization on the properties of HBr concrete.

• Strength and durability properties are improved by calcite precipitation produced by bacteria.

• CaCO3 Precipitation was confirmed in the microstructure analysis through FESEM and EDS.

Abstract

Cement is the main constituent of the concrete structure. Using rejected brick as pozzolana in replacement of cement reduced the utilization of natural resources, conserved the environment, and controlled waste disposal. Hydrated lime has been utilized as a chemical additive to improve the pozzolanic reaction of finely ground waste brick particles. This research investigates the process of biomineralization to enhance …

On The Prediction Of The Mechanical Properties Of Limestone Calcined Clay Cement: A Random Forest Approach Tailored To Cement Chemistry, Taihao Han, Bryan K. Aylas-Paredes, Jie Huang, Ashutosh Goel, Narayanan Neithalath, Aditya Kumar

Materials Science and Engineering Faculty Research & Creative Works

Limestone calcined clay cement (LC3) is a sustainable alternative to ordinary Portland cement, capable of reducing the binder's carbon footprint by 40% while satisfying all key performance metrics. The inherent compositional heterogeneity in select components of LC3, combined with their convoluted chemical interactions, poses challenges to conventional analytical models when predicting mechanical properties. Although some studies have employed machine learning (ML) to predict the mechanical properties of LC3, many have overlooked the pivotal role of feature selection. Proper feature selection not only refines and simplifies the structure of ML models but also enhances these models' prediction performance and interpretability. This …

Synergistic Effect Of Hedp.4na And Different Induced Pouring Angles On Mechanical Properties Of Fiber-Reinforced Alkali-Activated Slag Composites, Jingjie Wei, Jianwei Liu, Kamal Khayat, Wu Jian Long

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Poor Flexural and Damping Properties of Building Materials Damages Concrete Structures and Affects their Service Life When Concrete Structures Are Subjected to Dynamic Loads. Three Different Dosages (I.e., 0%, 0.3%, and 0.6%) of Organic Phosphonates (HEDP.4Na) and Different Pouring Methods (I.e., Conventional Pouring Method, 90°-Induced Pouring Method, and 150°-Induced Pouring Method) Were Designed to Improve the Flexural and Damping Performance of Fiber-Reinforced Alkali-Activated Slag Composites (FR-AASC). the Enhanced Mechanism of HEDP.4Na Was Revealed by Phase Analysis (X-Ray Diffraction, XRD), Pore Structure Analysis (Mercury Intrusion Porosimetry, MIP), the Heat of Hydration, and Scanning Electron Microscopy (SEM) Analysis. the Results Showed …

Behaviour And Material Properties Of Versaloc Semi-Interlocking Mortarless Masonry, Sonam Dorji, Hossein Derakhshan, David P. Thambiratnam, Tatheer Zahra, Alireza Mohyeddin

Research outputs 2022 to 2026

Masonry construction is popular around the world, but the use of mortared masonry presents numerous challenges. In recent decades, masonry construction systems incorporating interlocking masonry units have been proposed to eliminate mortar. The interlocking between masonry units can be achieved using specially shaped units. This paper presents a comprehensive experimental study to determine the behaviour as well as basic material properties of one such semi-interlocking mortarless masonry. The experiments included testings of ungrouted masonry units, prisms, and wallets. In addition, masonry prisms and wallets with grouted cores were also investigated to study the effect of grouting. A detailed description of …

The Compressive Strength And Microstructure Of Alkali-Activated Mortars Utilizing By-Product-Based Binary-Blended Precursors, Otman M. M. Elbasir, Megat A. M. Johari, Zainal A. Ahmad, Nuha S. Mashaan, Abdalrhman Milad

Research outputs 2022 to 2026

Researchers have investigated the feasibility of using ultrafine palm oil fuel ash (u-POFA) as a cement replacement material because of its potential to reduce the environmental impact of concrete production. u-POFA, a by-product of palm oil fuel combustion, is a suitable replacement for Portland cement in concrete mixes because of its sustainability and cost-effectiveness. This study investigated the microstructural and compressive strengths of alkali-activated mortars (AAMs) based on fly ash (FA) and granulated blast-furnace slag (GBFS) being added with varying percentages of u-POFA. The mixture samples were prepared in eighteen mortars using sodium metasilicate (Na2SiO3) as the source material and …

Optimization Of Mixture Parameter For Physical And Mechanical Properties Of Reactive Powder Concrete Under External Sulfate Attack Using Taguchi Method, Umut Bakhbergen, Chang Seon Shon, Dichuan Zhang, Jong Ryeol Kim, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reactive powder concrete (RPC) is defined as a cementitious composite material with an optimized size of granular constituents, very low water-to-binder ratio (w/b), pozzolanic materials like silica fume (SF), and discontinuous fiber reinforcement. RPC applications include bridge decks and girders, seismic columns, wind turbine towers, and pile foundations. Especially, a durable and robust RPC pile foundation with long service life is essential in building construction because continuous maintenance is impossible. Moreover, natural in-situ conditions such as water table, temperature, and sulfate concentration in soil to which the pile foundation is exposed are critical and related to deteriorating the pile foundation. …

Non-Destructive Evaluation Of Mortar With Ground Granulated Blast Furnace Slag Blended Cement Using Ultrasonic Pulse Velocity, Chi Kang Loke, Barry Lehane, Farhad Aslani, Subhra Majhi, Abhijit Mukherjee

Research outputs 2022 to 2026

Non-destructive evaluation using ultrasonic pulse velocity (V_p) testing has extensive applications in the concrete industry. With advances in construction technology, the use of ground granulated blast furnace slag (GGBFS) as a partial replacement to cement in a concrete mix is growing in popularity primarily because it reduces the initial capital cost of raw materials and the associated energy costs. This paper investigates the effect of the water-to-cement (w_c) ratio and the cement content replaced by GGBFS on the development with time of the ultimate compressive strength ((Formula presented.)) and the compression wave velocity (V …

A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Copper slag (CS), a by-product of copper smelting, is normally stockpiled, leading to wastes of resource and space as well as environment pollution. It has not been massively reutilized as a supplementary cementitious material in Portland cement due to its low reactivity. In the present study, CS is for the first time utilized as the base component to prepare an iron phosphate cement (IPC) by reacting with ammonium dihydrogen phosphate (ADP) at room temperature. The influence of the raw materials mass ratio (CS/ADP) on the microstructure and performance of IPC pastes are investigated. It is found that the compressive strength …

Technical And Economic Viability Of Distributed Recycling Of Low-Density Polyethylene Water Sachets Into Waste Composite Pavement Blocks, Celestin Tsala-Mbala, Koami Soulemane Hayibo, Theresa K. Meyer, Nadine Couao-Zotti, Paul Cairns, Joshua M. Pearce

Michigan Tech Publications

In many developing countries, plastic waste management is left to citizens. This usually results in landfilling or hazardous open-air burning, leading to emissions that are harmful to human health and the environment. An easy, profitable, and clean method of processing and transforming the waste into value is required. In this context, this study provides an open-source methodology to transform low-density polyethylene drinking water sachets, into pavement blocks by using a streamlined do-it-yourself approach that requires only modest capital. Two different materials, sand, and ashes are evaluated as additives in plastic composites and the mechanical strength of the resulting blocks are …

Predicting Compressive Strength Of Alkali-Activated Systems Based On The Network Topology And Phase Assemblages Using Tree-Structure Computing Algorithms, Rohan Bhat, Taihao Han, Sai Akshay Ponduru, Arianit Reka, Jie Huang, Gaurav Sant, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Alkali-activated system is an environment-friendly, sustainable construction material utilized to replace ordinary Portland cement (OPC) that contributes to 9% of the global carbon footprint. Moreover, the alkali-activated system has exhibited superior strength at early ages and better corrosion resistance compared to OPC. The current state of analytical and machine learning models cannot produce highly reliable predictions of the compressive strength of alkali-activated systems made from different types of aluminosilicate-rich precursors owing to substantive variation in the chemical compositions and reactivity of these precursors. In this study, a random forest model with two constraints (i.e., topological network and thermodynamic constraints) is …

Machine Learning Enabled Closed-Form Models To Predict Strength Of Alkali-Activated Systems, Taihao Han, Eslam Gomaa, Ahmed Gheni, Jie Huang, Mohamed Elgawady, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Alkali-activated mortar (AAM) is an emerging eco-friendly construction material, which can complement ordinary Portland cement (OPC) mortars. Prediction of properties of AAMs—albeit much needed to complement experiments—is difficult, owing to substantive batch-to-batch variations in physicochemical properties of their precursors (i.e., aluminosilicate and activator solution). In this study, a machine learning (ML) model is employed; and it is shown that the model—once trained and optimized—can reliably predict compressive strength of AAMs solely from their initial physicochemical attributes. Prediction performance of the model improves when multiple compositional descriptors of the aluminosilicate are combined into a singular, composite chemostructural descriptor (i.e., network ratio …

Solute Concentration Effects On Microstructure And The Compressive Strength Of Ice-Templated Sintered Lithium Titanate, Rohan Parai, Ziyang Nie, Raina Hempley, Gary M. Koenig Jr., Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

This work investigated the role of sucrose and cationic dispersant (1‐hexadecyl)trimethylammonium bromide concentration on ice‐templated sintered lithium titanate microstructure and compressive strength, to enable a comprehensive understanding of composition selection and elucidate processing–microstructure–mechanical property relationships. Sucrose and dispersant concentrations were varied to change total solute concentration in suspensions and viscosity. Dispersant was more effective in reducing viscosity than sucrose; however, their combination had an even greater impact on reducing viscosity. Based on viscosity measurements, a total of 12 suspension compositions were developed, and materials were fabricated at two different freezing front velocity (FFV) regimes. Solute concentration greatly influenced ice‐templated microstructure …

Mechanical Characteristics Of Cement Paste In The Presence Of Carbon Nanotubes And Silica Oxide Nanoparticles: An Experimental Study, Moses Karakouzian, Visar Farhangi, Marzieh R. Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh

Civil and Environmental Engineering and Construction Faculty Research

Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared using three different portions of MWCNT and NS. …

Predicting The Effect Of Fly Ash On Concrete’S Mechanical Properties By Ann, Mohammad Mehdi Roshani, Seyed Hamidreza Kargar, Visar Farhangi, Moses Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Fly ash, as a supplemental pozzolanic material, reduces concrete’s adverse environmental footprint by decreasing the emission of carbon dioxide (CO2 ) during the cement manufacturing process. Fly ash, which is a waste material, can enhance both the mechanical characteristics and durability of concrete, and has the capability to play an important role in sustainable design. Considering the widespread interest in applying Fly ash, and despite research studies, the level of replacement is still unclear. In this paper, a novel method using artificial neural networks (ANN) is presented to predict concrete’s mechanical …

Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman

Publications and Research

Geopolymers are the results of geosynthetic reactions between aluminosilicates and strong bases. This results in chemical bonds between aluminum (Al), Silicon (Si)and oxygen (O) composing polymer rings in tetrahedral coordination. These bonds give them widespread useful applications such as high heat bearing ceramics, and base construction material whilst being far more environmentally conscious. The purpose of the experiment is to examine the effect of Silicon Carbide whisker and inorganic glass particles on thermal and mechanical properties of Geopolymers. This study will help understand the effect of various compositions and concentrations of SiO₂ in mechanical strength. In this experiment, the …

Mechanical Properties Of Hydrogenated Amorphous Silicon (A-Si:H) Particles, Taizhi Jiang, Fardin Khabaz, Aniket Marne, Chenglin Wu, Raluca Gearba, Revanth Bodepudi, Roger T. Bonnecaze, Kenneth M. Liechti, Brian A. Korgel

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A nanoindenter was used to compress individual particles of hydrogenated amorphous silicon (a-Si:H) ranging in diameter from 290 nm to 780 nm. The colloidal synthesis used to produce the particles enables the hydrogen content to be manipulated over a wide range, from about 5 at. % to 50 at. %, making these a-Si:H particles promising for applications in lithium ion batteries, hydrogen storage, and optical metamaterials. Force-displacement curves generated using a tungsten probe flattened with focused ion beam exhibited elastic and then plastic deformations, followed by fracture and crushing of the particles. For particles with 5% and 50% H, Young's …

The Effect Of Fine And Coarse Recycled Aggregates On Fresh And Mechanical Properties Of Self-Compacting Concrete, Mahmoud Nili, Hossein Sasanipour, Farhad Aslani

Research outputs 2014 to 2021

Today, the use of recycled aggregates as a substitute for a part of the natural aggregates in concrete production is increasing. This approach is essential because the resources for natural aggregates are decreasing in the world. In the present study, the effects of recycled concrete aggregates as a partial replacement for fine (by 50%) and coarse aggregates (by 100%) were examined in the self-compacting concrete mixtures which contain air-entraining agents and silica fumes. Two series of self-compacting concrete mixes have been prepared. In the first series, fine and coarse recycled mixtures respectively with 50% and 100% replacement with air entraining …

Development Of Heavyweight Self-Compacting Concrete And Ambient-Cured Heavyweight Geopolymer Concrete Using Magnetite Aggregates, Afsaneh Valizadeh, Farhad Aslani, Zohaib Asif, Matt Roso

Research outputs 2014 to 2021

Heavyweight self-compacting concrete (HWSCC) and heavyweight geopolymer concrete (HWGC) are new types of concrete that integrate the advantages of heavyweight concrete (HWC) with self-compacting concrete (SCC) and geopolymer concrete (GC), respectively. The replacement of natural coarse aggregates with magnetite aggregates in control SCC and control GC at volume ratios of 50%, 75%, and 100% was considered in this study to obtain heavyweight concrete classifications, according to British standards, which provide proper protection from sources that emit harmful radiations in medical and nuclear industries and may also be used in many offshore structures. The main aim of this study is to …

Fire Performance Of Heavyweight Self-Compacting Concrete And Heavyweight High Strength Concrete, Farhad Aslani, Fatemeh Hamidi, Qilong Ma

Research outputs 2014 to 2021

In this study, the fresh and hardened state properties of heavyweight self-compacting concrete (HWSCC) and heavyweight high strength concrete (HWHSC) containing heavyweight magnetite aggregate with 50, 75, and 100% replacement ratio, and their performance at elevated temperatures were explored experimentally. For fresh-state properties, the flowability and passing ability of HWSCCs were assessed by using slump flow, T500 mm, and J-ring tests. Hardened-state properties including hardened density, compressive strength, and modulus of elasticity were evaluated after 28 days of mixing. High-temperature tests were also performed to study the mass loss, spalling of HWSCC and HWHSC, and residual mechanical properties at 100, …

Properties Of Ambient-Cured Normal And Heavyweight Geopolymer Concrete Exposed To High Temperatures, Farhad Aslani, Zohaib Asif

Research outputs 2014 to 2021

Ambient-cured heavyweight geopolymer concrete (HWGC) is a new type of concrete that combines the benefits of both heavyweight concrete (HWC) and geopolymer concrete (GC). HWGC provides proper protection from the sources that emit harmful radiations in medical and nuclear industries. Furthermore, HWGC may also be used in offshore structures for pipeline ballasting and similar underwater structures. In this study, heavyweight aggregates (magnetite) have been used and replaced by normal-weight coarse aggregates in GC at volume ratios of 50, 75, and 100% to attain heavyweight classification according to British standards. This study investigates the impacts of high temperatures on standard ambient-cured …

Investigating The Use Of In-Place Lateral Pull Off Tests To Determine The Compressive Strength Of Structural Concrete, Charlie Sun

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet’s current practice for determining the compressive strength of structural concrete consists of two methods. Both methods require that samples be delivered to an off-site facility for testing. Accordingly, affected parties on the project site must wait for the delivery of samples to the off-site facility, the performance of tests and analysis of test data, and the return of test results to the project site. Analysis of existing structural concrete requires core samples to be taken from the structural element in question. As a result, sample locations must be patched and repaired. Sampling can also potentially damage …

Beta-Type Ti-Nb-Zr-Cr Alloys With Large Plasticity And Significant Strain Hardening, Syed F. Jawed, Chirag D. Rabadia, Y. J. Liu, L. Q. Wang, Y. H. Li, X. H. Zang, Laichang C. Zhang

Research outputs 2014 to 2021

A series of Ti-25Nb-8Zr-xCr (x = 0, 2, 4, 6, 8 wt%) alloys were designed based on DV-Xα cluster method and e=a-Δr diagram with an anticipation to obtain high plasticity and significant strain hardening. The designed alloys were produced through cold crucible levitation melting technique in order to effectively investigate their micro-structures and mechanical properties. The addition of Cr significantly enhances the β stability in the microstructures of the Ti-25Nb-8Zr-xCr alloys. Both yield strength and hardness of the studied alloys increase due to the effect of solid-solution strengthening. By contrast, the plasticity, maximum strength and strain hardening rate are influenced …

Investigation Of Setting Time And Compressive Strength Of Ready-Mixed Concrete Blended With Returned Fresh Concrete, Negasi N. Gebremichael, S. Mahmoud Motahara Karein, Moses Karakouzian, Kazem Jadidi

Civil and Environmental Engineering and Construction Faculty Research

Returned fresh mix concrete (RFC) is a problem with both economic and environmental impacts. Therefore, investigators have recommended various ways to decrease the amount of RFC in manufacturing facilities. Among the most common procedures are dumping concrete in landfill, recycling it, using the aggregate, and using it to produce concrete blocks. In this study, the authors investigated the behavior of various proportions of RFC mixed with ready-mix plain and retarded concrete. The authors also studied the influence of aging by producing specimens after one, two, three, and four hours. In addition, the researchers investigated controlled and uncontrolled environments by mixing …

A High-Entropy Alloy With Hierarchical Nanoprecipitates And Ultrahigh Strength, Zhiqiang Fu, Lin Jiang, Haiming Wen, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

High-entropy alloys (HEAs) are a class of metallic materials that have revolutionized alloy design. They are known for their high compressive strengths, often greater than 1 GPa; however, the tensile strengths of most reported HEAs are limited. Here, we report a strategy for the design and fabrication of HEAs that can achieve ultrahigh tensile strengths. The proposed strategy involves the introduction of a high density of hierarchical intragranular nanoprecipitates. To establish the validity of this strategy, we designed and fabricated a bulk Fe₂₅Co₂₅Ni₂₅Al₁₀Ti₁₁₅ HEA to consist of a principal face-centered cubic …

Ultrasonic Techniques For Air Void Size Distribution And Property Evaluation In Both Early-Age And Hardened Concrete Samples, Shuaicheng Guo, Qingli Dai, Xiao Sun, Ye Sun, Zhen Liu

Department of Civil, Environmental, and Geospatial Engineering Publications

Entrained air voids can improve the freeze-thaw durability of concrete, and also affect its mechanical and transport properties. Therefore, it is important to measure the air void structure and understand its influence on concrete performance for quality control. This paper aims to measure air void structure evolution at both early-age and hardened stages with the ultrasonic technique, and evaluates its influence on concrete properties. Three samples with different air entrainment agent content were specially prepared. The air void structure was determined with optimized inverse analysis by achieving the minimum error between experimental and theoretical attenuation. The early-age sample measurement showed …

Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …

Evaluation Of Carbonation Resistance Of Paint Coated Concrete For Buildings, Tommy Y. Lo, Wenyu Liao, C. K. Wong, Waiching Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When evaluating the carbonation resistance of paint coated concrete, the effects of both the strength grade and the curing conditions (standard curing and accelerated curing) of concrete substrate on carbonation resistance of paint coated concrete were investigated. The concept of the carbonation suppression ratio of paint was presented for evaluation of the anti-carbonation performance of the two types of paints (exterior and interior paints) when applied to a reference concrete substrate. The test results showed a good linear relationship between the carbonation depths of the paint coated concrete and the square root of exposure times. Concrete with higher strength grade …