2025
GEMS: Geoengineered Materials Solutions
Funded by: Engineer Research and Development Center - Geotechnical and Structures Lab
Abstract:
The U.S. military projects power around the globe to support the strategic initiatives of the United States. To support power projection, the military is required to design, build, maintain, repair, and rehabilitate various infrastructure elements including geotechnical structures, roads, bridges, rail, and airfields at permanent installations and in contested environments globally. In constructing permanent infrastructure, the DoD prefers to identify and employ long lasting and sustainable materials to minimize maintenance operations. In contested environments, the DoD has a capability shortfall to rapidly repair damaged or deteriorated infrastructure expediently and with limited material solutions.
Combat engineers routinely face challenges including, but not limited to, craters in roads and airfields, damaged culverts, constructing alternate gap crossings, repair of bridge components, and reinforcement of damaged walls. Further complicating this problem is the large logistical footprint required for traditional combat engineering construction solutions. High quality repair materials are unlikely to be readily available at the point of need and are logistically intensive to transport from a port of origin. The research conducted under the GEMS project will facilitate expedient assessment, repair, and construction of horizontal infrastructure to support logistical throughput of existing lines of communication (LOCs) and air and seaports of debarkation (APODs and SPODs).
The GEMS project proposes to develop novel prototype solutions to rapid, expeditionary construction challenges. The proposed prototype solutions will center around mechanically stabilized earth (MSE) wall systems for DoD applications; rapid asphalt repair tactics, techniques, and procedures (TTPs); accelerated concrete material mixture designs; short-gap crossings using indigenous timber; subsurface condition
2024
Contingency Infrastructure Development - Rapid Infrastructure and Development (RIDE) – Construction of Deployable Bridge Prototype
Project Completed: 2026
Funded by: Engineer Research and Development Center - Geotechnical and Structures Lab
Abstract:
Rapid Infrastructure Development (RIDE) is an ongoing project at the University of Arkansas related to fast deployment and repair of military infrastructure. One task of this project involves developing a rapidly deployable bridge concept that can be utilized by a small team of front-line soldiers. The first phase of this project ended in March 2024 and involved selecting preliminary member sizes and developing finite element analysis (FEA) models for two selected bridge concepts. The current phase of the project involves the construction of a prototype bridge based on the more promising of the two developed bridge concepts. This prototype will be a full scale model to be tested under actual design service loads. The final deliverable is expected to be a parts list and executed prototype of an easily deployable gap crossing for gaps up to 25-30 feet.
MarTREC 6017: Development of Rapid Setting Soil-Cement Mixture Designs and Performance Testing
Project Completed: 2024
Funded by: Maritime Transportation Research and Education Center
Abstract:
Flooding in the past few years in the U.S. has shown the concerning condition of the country´s waterway systems and the great economic impact that arises from the repair costs associated with damage to such structures, as well as the disruptions caused by their closure during downtime for repairs. Levee failures not only disrupt navigable waterways, but they can also impact rail and truck transportation. Additionally, floods can result in damage to other soil structures impacting transportation and the movement of goods including riverbanks, dams, and highway embankments. Several of these levee failures and failures of other soil-based infrastructure are due to instabilities caused by internal and overtopping erosion. Even though there are existing flood-fighting methods such as sandbagging, sand boil ringing, and tarping exposed soil, most are temporary treatments and the levees eventually require repair. Usually, the repairs require long downtimes that are difficult to carry out during flood season, and they can be quite expensive. Therefore, fast-setting soilcement could be a cheaper and more effective alternative for short-term repair during flood season, as well as long-term repairs of the levee. Rapid setting soil-cement can utilize onsite soils, which reduces transportation and labor costs and it can be used to create a strong surface armoring in a matter or hours or even minutes. Conventional portland cement-based soil-cement has been commonly used as the repair method for waterway structures for decades, but the rapid setting time, strength gain, and reduced shrinkage of rapid-set cements such as belite calcium sulfoaluminate (BCSA) make it a promising alternative to conventional cement for such flood repair efforts. This project studies the effectiveness of various proportions of BCSA soil-cement mixtures by measuring their early age compressive strength and their performance under simulations of piping conditions through the Hole Erosion Test.
2023
Advanced Environment-Friendly Concrete Materials for Rapid Infrastructure Repair and Rehabilitation
Project Completed: 2025
Funded by: Southern Plains Transportation Center
Abstract:
The United States has many infrastructure challenges in terms of maintaining and repairing an extensive network of highways and structures that are aging. Additionally, an increased focus on environmentally friendly processes and materials means that there is an urgent need to develop and evaluate alternative cementitious materials and novel Portland cement-based solutions to infrastructure maintenance issues. One promising technology is the utilization of calcium sulfoaluminate (CSA) cements in the production of concrete materials. CSA cements offer several advantages including lower carbon intensity compared to portland cement, rapid setting, and low shrinkage. These properties make them an ideal candidate for rapidly replacing or repairing critical transportation infrastructure. In addition, Engineered Cementitious Composites (ECCs) with superior ductility and mechanical strength have been proposed as a promising material alternative to extend the durability and service life of infrastructure. However, ECC typically requires a high cement content, leading to challenges such as increased hydration heat, autogenous shrinkage, and higher carbon dioxide emissions. To address these challenges, the project aims to investigate the feasibility of using CSA as a partial or complete replacement for cement in ECC without sacrificing its mechanical properties, specifically tensile ductility. The addition of CSA in concrete and ECC materials will be tested separately at the performing institutions and the PIs have planned activities to enhance the collaboration between the University of Arkansas and Louisiana State University by sharing research findings, pursuing further collaborations, and strengthening the connections between the researchers.
2022
ARDOT TRC 2203: Low Shrinkage Concrete Mixtures for Arkansas
Project Completed: 2024
Funded by: ARDOT
Abstract:
While most bridge decks in Arkansas perform adequately over their design life, early-age shrinkage cracking is a recurring issue in some bridges that can lead to compromised durability. Shrinkage cracks may lead to serious deterioration such as rebar corrosion and freezing and thawing damage. This shrinkage can be reduced by changing the mixture design or materials, improving construction procedures, and changing structural design parameters.
The objectives of this study are two-fold:
1) Determine the effect of various Arkansas coarse aggregates on the drying shrinkage in standard bridge deck mixtures, and
2) develop a low-shrinkage concrete specification modeled on other state specifications tailored to Arkansas materials.
A review of approved quarries on the ARDOT QPL reveals a minimum of 7 major coarse aggregate types approved for use in ARDOT concrete. Therefore, though bridge decks may contain the same cementitious content and utilize similar construction practices, drying shrinkage may be much more of a concern with specific Arkansas aggregates. Determining the impact of aggregate type on drying shrinkage would help reduce bridge deck cracking and improve long-term durability.
Considering the development of low-shrinkage specifications, the approach will be two-fold. First, materials recommendation will be developed (a maximum cement content, suggested aggregate/admixture interventions). Secondly, a performance test will be recommended (maximum drying shrinkage by ASTM 157 (ASTM Standard C157 2017) or AASHTO T160) to ensure the quality of the low-shrinkage concrete mixture. The suggested mixtures in this project may include lightweight aggregate (to reduce concrete modulus), shrinkage reducing admixture, and/or fly ash to cause the lowest amount of shrinkage. The resulting mixture design specification can be used for bridge deck concrete to ensure long-lasting bridges.
Development of an Innovative Rapidly Constructible Bridge
Project Completed: 2023
Funded by: Engineer Research and Development Center - Geotechnical and Structures Lab
Abstract:
This project is a preliminary concept study to develop creative solutions for the rapid deployment of temporary bridge structures, considering bridge super-structure and deck deployment. In this project, compact tensegrity super-structures are considered along with origami-inspired cement-impregnated decking or more traditional concrete decks made with lightweight concrete. It is anticipated that the project will result in a rapidly deployable bridge configuration (from storage to function within a few hours) that is capable of transporting military vehicle loads over short-to-medium spans. This project will develop advanced pavement technologies for rapid deployment, and lay the groundwork for future prototyping and strength verification studies. This project is expected to be a feasibility study, as such it focuses on finite element modeling, small scale prototyping, mixture design, and exploratory testing rather than construction or delivery of a working bridge system.
ARDOT TRC 2204: Materials and Testing Specifications for Drilled Shaft Concrete
Project Completed: 2026
Funded by: ARDOT
Abstract:
Drilled Shafts are a common bridge foundation system used in Arkansas. Previous research has established best practices for mixture designs, mixing, placing, and testing drilled shaft concrete, but this work has not been implemented in Arkansas. Self-consolidating concrete can be used in drilled shafts to solve issues of aggregate segregation and consolidation. The purpose of this project is to determine a mix design for SCC that can be utilized across the state. Along with a new mix design, testing procedures are needed for SCC in the field, as well as specification for required QA/QC testing of drilled shaft concrete.
2021
ACI Foundation - Concrete Research Council: Stress-Strain Analysis of BCSA Cement for Structural Applications
Project Completed: 2023
Funded by: American Concrete Institute Foundation
Abstract:
The current edition of the ACI 318-19(22) Building Code Requirements for Structural Concrete and Commentary allows the use of alternative cements in design when these materials can be proved to conform to the existing structural design parameters used to estimate performance. Belitic calcium sulfoaluminate (BCSA) cement is an alternative hydraulic cement which exhibits fast setting properties, high sulfate resistance, adequate durability, and low carbon emissions when compared with portland cement. Limited research exists to characterize the performance of BCSA cement concrete in ultimate strength design. This report compares the stress-strain relationship of BCSA cement concrete in both uniaxial compression and flexural compression loading to that of portland cement concrete. Also, guidance is provided on the applicability of current ACI code values for the design of BCSA cement concrete flexural members. A total of 64 concrete cylinders at various water cement ratios (w/c) and ages were tested uniaxially and strains were measured to determine static modulus of elasticity (MOE). Of the 64 cylinders, 6 control cylinders of portland cement concrete (PC) and 58 BCSA cement concrete specimens were made. From these tests, uniaxial stress-strain relationships were developed, and MOE and maximum strain values occurring at maximum stress were compared with historical data and design code estimations. 14 unreinforced flexural compression specimens at various w/c and ages were fabricated and tested in combined axial compression and bending to evaluate compression zone properties of BCSA cement concrete for reinforced concrete design. Variables in this study included w/c, age at testing, and compressive strength. Results from flexural compression specimen testing were compared with historical results and design code estimates. Results from uniaxial compression cylinder tests indicated that BCSA cement concrete behaves similarly to PC concrete in compression and has similar MOE and compression strain characteristics. Results from flexural compression specimens suggest that concrete design code equations for estimating design parameters for flexural members are adequate or conservative for BCSA cement concrete flexural members with strengths between 7.8 and 12.4 ksi.
Flexural testing set up for measuring the flexural stress-strain response of concrete
Specimen failure in slow motion
2020
Advanced Concrete Research and Development for Military Applications
Project Completed: 2023
Funded by: US Army Corps of Engineers ERDC GSL
Abstract:
The goals of this project were to develop alternative testing and mixture design solutions to military infrastructure problems related to concrete. This includes developing concrete mixtures with alternative cements for a variety of applications, developing new ASR mitigation strategies and test methods, and creating new self-stressing UHPC mixtures. The work in this project was divided into 5 tasks which involved multiple researchers in the Department of Civil Engineering at the University of Arkansas.
2019
Investigating Concrete Deck Cracking in Continuous Steel Bridges
Project Completed: 2022
Funded by: Arkansas DOT
Abstract:
Concrete bridge deck cracking can cause serious serviceability issues during a bridge’s design life and compromise a bridge’s structural strength. Cracks allow water and chemical ingress, which accelerate road surface and structure damage. ARDOT has identified bridge deck cracking shortly after decks are placed and prior to applying live loads. The causes of bridge deck cracking are uncertain. Many contractors are currently using continuous deck pours at Arkansas bridges. However, this construction approach restricts concrete slab movement during shrinkage. After concrete cracking is initiated, cracks may enlarge due to excessive service load stresses.
The interaction between the concrete deck and girder flange restricts concrete slab shrinkage and therefore induces tensile stresses. Stresses developing in the concrete deck and bridge girder are a function of the bridge girder stiffness. The transition from Allowable Stress Design (ASD) to Load Factor Design (LFD) to Load and Resistance Factor Design (LRFD) has resulted in bridge girders designed with a lower stiffness. The impact of bridge pouring procedure, shrinkage, and girder stiffness need to be investigated to determine causes for bridge deck cracking at Arkansas continuous steel bridges. After determining the cause for bridge deck cracking, long term corrective measures will be recommended to ARDOT for implementation to prevent future cases of bridge deck cracking. Regardless of what causes bridge deck cracking, it is important to limit cracking in bridge decks to ensure a long lasting structure with minimal maintenance needs.
Capillary Pressure Sensor Testing to Identify Curing Regimen in Freshly Placed Bridge Decks
Project Completed: 2020
Funded by: Arkansas DOT
Abstract:
The overall performance of concrete in bridge decks can be affected by the curing regimen. The Department now recognizes and allows concrete curing compounds that are lithium based. But, do they outperform the standard curing regimens? With the advent of new testing equipment for freshly placed concrete, Capillary Pressure Sensor System (CPSS), the evaporation effects can be measured. By measuring the capillary pressure during the initial set period after finishing, shrinkage cracks can be avoided by adding moisture and/or curing compound to the concrete surface when the alarm is triggered by threshold pressure limit. Additional curing compound and/or moisture can be added to reduce or mitigate the effects of the evaporation. ARDOT currently allows the use of lithium cure under a special provision when the contractor requests it. This project would use the CPSS to evaluate the different curing regimens the contractor uses and determine which product and/or method works best.
This project aims to investigate the use of a CPSS to monitor the development of capillary pressures in the surface of fresh concrete bridge decks or pavements. This capillary pressure can be used to determine if plastic shrinkage cracking is likely to occur and alert the user when moisture should be added to the surface to prevent cracking. The sensor will be tested in the lab to verify its ability to measure plastic shrinkage pressures, then lab testing will be performed to compare curing techniques. A field study will help determine if the sensor is useful in practice to ARDOT and to contractors.
Using CSA Cement for Novel Waterway Repair Materials
Project Completed: 2021
Funded by: MarTREC
Abstract:
The health and performance of maritime transportation infrastructure is critical to the nation’s economic and social prosperity. Much of this infrastructure has well exceeded its 50-year design life and is often in need of repair. Because waterway transportation structures are difficult to detour, the time taken by repairs is of critical importance. The fastest repair techniques should be developed in order to minimize the time out of service. The objective of this research is to investigate the properties and behavior of Calcium Sulfoaluminate-Belite (CSA) cement mixtures for waterway repair applications. CSA cement is a rapid setting, low-shrinkage cement which can be used to form advanced new materials capable of quickly repairing the nation’s maritime infrastructure. CSA cement maintains many of the beneficial qualities of portland cement but it can reach structural strengths in only a few hours and its low shrinkage makes it an ideal repair material.
Improved Mix Designs to Resist Microbially Induced Concrete Corrosion
Project Completed: 2021
Funded by: City of Fayetteville, AR
Abstract:
Some concrete manholes in Fayetteville, AR are experiencing a reduced service life due to microbially induced corrosion (MIC). The sewage or wastewater in the manholes creates conditions that are conducive to certain types of anaerobic bacteria. This bacteria attaches to the concrete and sets off a chain of reactions that ultimately lead to formation of sulfuric acid. This sulfuric acid then attacks the concrete, causing expansion and cracking. City engineers want to investigate design alternatives that will lead to longer lasting manholes resistant to MIC. The goal of this work is to compare alternative concrete mix design solutions to provide better resistance to MIC.
Journal paper published from work
CTS Cement Manufacturing Corporation Gift
CTS Cement Manufacturing Corporation is supporting students who are interested in studying Belitic Calcium Sulfoaluminate cement at the University of Arkansas. At the moment, these students are studying mix proportioning guidelines for BCSA cement, the effects of set retarders, and mechanical properties.
2018
Monitoring moisture in the cross laminated timber panels of the UA Stadium Drive Residence Halls
Project Completed: 2021
Funded by: US Endowment for Forestry and Communities
Abstract:
At the 2nd North American Mass Timber Research Workshop, the moisture behavior in cross laminated timber (CLT) was recognized as a major topic for the research community to clarify and understand. Very little data exist on the long-term movement of the moisture in CLT during a building’s construction and operation. In addition, the wetting of mass timber during construction raises serious concerns about high moisture content in CLT that could lead to decay and mold (compromising the air quality) or decrease the strength and stiffness of the material.
For a better comprehension of the moisture conditions present in mass timber constructions, a long-term moisture monitoring program will be implemented on a mass timber framed building located on the University of Arkansas campus. The University of Arkansas Stadium Drive Residence Halls building that is currently under construction is built with CLT and will be monitored in this project. The building will be monitored with an array of Omnisense wireless moisture meters to track moisture content throughout the building’s construction and post-occupancy operation. Moisture has been monitored in this fashion in other research projects, but these buildings will be the first studies on moisture in CLT in the southern United States.
Development of Rating Tool for Prestressed Concrete Bridges Vulnerable to Shear
Project Completed: 2019
Funded by: Oklahoma DOT
Abstract:
A study was conducted examining the factors affecting shear capacity and load rating, two potential methods for assessing condition of in-service prestressed concrete bridge girders, and a simple procedure for assessing whether and how a bridge should be rated for shear was developed. First, a detailed literature review was conducted to collect results of experimental shear testing on older prestressed concrete girders and the comparison of those results to capacity calculation methods. This was followed by a parametric study to examine the effect of different design items on load distribution and the difference between AASHTO load distribution equations and grillage models for more than two hundred different bridge configurations. Two methods for assessing condition of in-service girders were examined and further refined. The results of previous shear testing and the grillage model parametric study indicate that there may be conservativism built in when AASHTO load distribution factors are used that leaves open the possibility of increased load ratings for some older bridges. Using a grillage model can increase load ratings, reducing the potential need to load post or take some bridges out of service without sacrificing accuracy and safety. The proposed procedure uses a set of simple criteria to identify bridges potentially vulnerable to shear and modifications to the typical rating procedure to produce an accurate shear rating.
Arkansas/Oklahoma Chapter American Concrete Pavement Association Gift
The Oklahoma/Arkansas chapter of the ACPA pledged to give $100,000 per year for 5 years to support concrete pavement related initiatives. This money is being used to support students who are interested in studying concrete pavements.
The first students to be supported by this generous gift are Casey Jones (advised by Dr. Micah Hale), and Yancy Schrader. Currently they are working on understanding calcium oxychloride formation and mitigation in concrete pavements, and improving upon test methods to categorize fly ashes based on their susceptibility to de-train air from concrete.
Links:
$500,000 Gift Paves the Way for Concrete Research at the UofA
Chapter Pledges Research Funds
Gift to fund study of concrete paving
ACPA Chapter Gift to Fund Concrete Pavement Research at U of A
2017
Early Life Flexural Performance and Behavior of Reinforced BCSA Concrete Beams
Project completed: December 2018
Funded by: Material donated by CTS Cement
Abstract:
Belitic calcium sulfoaluminate cement (BCSA) is a hydraulic, rapid setting alternative to ordinary portland cement (OPC) with reduced energy demands and CO2 emissions. BCSA cement has numerous current and potential applications including transportation repair and precast manufacturing. Currently, limited research exists regarding the structural performance of CSA cements, restricting its potential implementation. Thus, the purpose of this research is to provide insight into the flexural performance and behavior of reinforced BCSA concrete beams. Overall, BCSA concrete had similar cracking and loading behavior to the OPC beams, with increased moment capacity for compression controlled specimens. Furthermore, BCSA concrete showed increased tensile strength and ductility when compared to OPC. Overall, the flexural strength of the BCSA concrete exceeded the predicted flexural strengths, indicating the current flexural strength equations are applicable for BCSA reinforced concrete design