Engineering Commons^™

Assessment Of Deteriorated Structural Concrete To Provide Durable Repairs, Theodore Hopwood, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

Most of the structural elements on Kentucky bridges are made of reinforced concrete. Many of these elements deteriorate as a result of corrosion of the reinforcing steel caused by carbonation and — primarily — applications of chlorides by the Kentucky Transportation Cabinet (KYTC). Corrosion of reinforcing steel is reviewed along with assessment procedures that leverage nondestructive evaluation (NDE) methods and related laboratory and field tests. Several maintenance procedures are discussed, including the application of sealers and coatings, patch and major concrete repairs, and electrochemical methods. Incorporating NDE and test results into maintenance procedure selection is discussed. Recommendations are provided on …

Waterproofing Options For Bridge Decks, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Due to the increasing use of deicing chemicals and the subsequent intrusion of chlorides into bridge decks, it is necessary to expand the use of available protective measures, including waterproofing materials. Waterproofing options that fall into three categories; 1) membranes (liquid and sheet systems), 2) friction polymers (laminates), and 3) polymer asphalts. This study assessed the waterproofing characteristics of these products. Prior to this study, no common test had been established to compare the performance of waterproofing products. A test method was developed that closely follows ASTM D5084, “Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials …

Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the Kentucky Transportation Cabinet (KYTC) can result in problematic levels of chloride at steel reinforcing depths in a relatively short amount of time. With the advent of liquid applied pre-treatment deicing chemicals, testing performed in Kentucky indicate chloride levels in bridge decks at a depth of two inches have increased significantly.

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the …

Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

One of the growing number of preventive bridge maintenance activities conducted by the Kentucky Transportation Cabinet (KYTC) is washing and applying thin film protective coatings to bridge abutments and piers. Previous work conducted by Kentucky Transportation Center (KTC) under KYSPR 10-406 documented increased chloride contamination of these bridge components and the need for protective coatings. KYTC Contract ID 162952 includes, among other tasks, cleaning and coating specific concrete elements of eighteen bridges in Anderson and Woodford counties (District 7). These elements are interior faces of the barrier walls, pier caps, and abutment seats. The contract was let on July 29, …

Evaluation Of Deterioration Of Structural Concrete Due To Chloride Intrusion And Other Damaging Mechanisms, Sudhir Palle, Brian K. Howell, Theodore Hopwood Ii, Bobby W. Meade

Kentucky Transportation Center Research Report

Kentucky's bridges continue to age and experience distress. The intrusion of chlorides into concrete remains the primary mechanism for deterioration. It leads to reinforcing steel corrosion that damages the adjoining concrete structure. This study found problematic chloride concentrations in Kentucky concrete bridge elements (decks, pier caps, abutments). Chloride levels have been found at concentrations sufficient to initiate reinforcing steel corrosion. In some cases, chloride concentrations were sufficient to cause accelerated corrosion and produce major section loss of reinforcing steel. Advanced stages of corrosion such as these typically require costly repairs and maintenance to extend the service life of bridges.

Field …

Qc/Qa: Evaluation Of Effectiveness In Kentucky, Kamyar C. Mahboub, Paul M. Goodrum, Andy Glasglow, Jason Enlow, Nick Hendrix, Moin Uddin

Kentucky Transportation Center Research Report

Quality control and quality assurance in the highway industry is going through a cultural shift. There is a growing trend toward using the contractor data for acceptance and payment purposes. This has led to serious concerns about conflicts of interests. The question remains: are there adequate safeguards in place? To address these concerns, a number of asphalt and concrete QC/QA projects in Kentucky were examined and statistical analyses were conducted. This report presents a summary of findings and recommendations. Generally speaking, the Kentucky experience revealed that the QC/QA system is working well, and the agency’s random inspection data when compared …

Experimental Concrete Coating Application On The Median Barrier Of I-65 In Louisville, Rick Younce, Theodore Hopwood Ii, Sudhir Palle

Kentucky Transportation Center Research Report

The objectives of this research were to evaluate the experimental protective coating that was applied to approximately 1,200 linear feet of concrete median barrier along the paving project on a section of I 65 between mile points 131.289 and 136.421 in downtown Louisville.

The project was completed generally in accordance with the specifications and special notes. This experimental project is the first trial of concrete coatings identified under KYSPR 05-271 Coatings, Sealants and Fillers to Address Bridge Concrete Deterioration and Aesthetics-Phase 1. The coatings systems identified under that study were intended to provide improved protection and aesthetics for reinforced concrete. …

Coatings, Sealants, And Fillers To Address Bridge Concrete Deterioration And Aesthetics-Phase 1, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

This study addresses experimental evaluation and testing of concrete coatings for maintenance purposes on structural (steel reinforced) concrete. The test methods employed are intended to identify coatings and sealers for eventual incorporation into a qualified products list for structural concrete coatings. Some of the methods/procedures used in this study will be used in the future to evaluate additional coatings and sealers. Developmental work focused on identifying relevant coatings systems and laboratory tests. The objectives of experimental project monitoring were to: 1) identify existing viable concrete coatings along with their properties/ characteristics/surface preparation requirements and determine effective acceptance/evaluation tests for those …

Examination Of Concrete Cores From Lowe’S Store In Bowling Green, David L. Allen, L. John Fleckenstein

Kentucky Transportation Center Research Report

The Kentucky Transportation Center was requested by Mr. Tom Brock, Vice President of McWhorter and Company, Inc., to examine cores obtained from a PCC floor slab of a Lowe's store in Bowling Green, Kentucky. From a telephone conversation with Mr. Brock, is was our understanding that a large portion of the surface of the floor slab was scaling and becoming detached. This apparently involved approximately the top 118 inch of the slab.

Nine cores were delivered to our laboratories. They were obtained at the locations shown in the floor map included in Appendix A. Those nine cores are shown in …

Performance Survey Of Silicone-Sealed Concrete Pavement Joints, David Q. Hunsucker, Edgar E. Courtney

Kentucky Transportation Center Research Report

This report summarizes field inspections of various silicone-sealed concrete pavement joints. A list of silicone sealant projects was provided by the Kentucky Transportation Cabinet. Observations of performance were subjective and qualitative.

Bridge Decks And Overlays, James H. Havens, Theodore Hopwood Ii, Edgar E. Courtney

Kentucky Transportation Center Research Report

The report presents a historical perspective of the Transportation Cabinet's bridge deck construction and maintenance efforts directed toward increasing bridge deck durability.

Bridge decks crack in specific patterns that primarily depend upon bridge designs. Normal deck cracking is due to load-induced and thermal effects. Each type of cracking has a distinct pattern.

One-hundred and nineteen experimental bridge deck overlays were inspected. Included were 9 membrane bridges, 87 latex concrete overlays and 23 low-slump overlays. The overlays had been placed originally on both new and existing bridge decks on various routes throughout the state. Most of the overlays were rated in …

Shrinkage Compensation Deck Concrete (Ky 1974 Bridge Over Tates Creek Road), David Q. Hunsucker

Kentucky Transportation Center Research Report

This report summarizes the construction activities on an experimental bridge deck utilizing shrinkage compensating concrete. The experimental concrete is characterized in terms of freeze/thaw durability, compressive strength, and elastic moduli.

Thickness Design Curves For Portland Cement Concrete Pavements, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

Past experience indicates that thickness designs using portland cement concrete best agree with criterion used in the Portland Cement Association's design method for 18-kip EAL of 2 to 3 million or less. For EALs greater than 2 to 3 million, past experience best agrees with criterion developed from the AASHO Road Test. Research herein indicates the two criterion become asymptotic to each other at approximately 2.5 million EAL. For a variation in thickness and elastic moduli in portland cement concrete, dense-graded aggregate, and sub grade elastic modulus, research indicates that a general conic equation (included herein) very closely duplicates the …

Low-Void Concrete Mixtures, Assaf S. Rahal, James H. Havens

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable liquid material and(or) a super-water-reducer or plasticizer -- thus producing a low-void concrete. A water-cement ratio of 0.244 - 0.30 was presumed minimal for hydration of the cement. Several polymeric materials, asphalts, oils, and superplasticizers were used. Success was achieved with two latexes, one epoxy, and several superplasticizers. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.

An Investigation Of Low Cylinder-Strengths (District 6), Assaf S. Rahal

Kentucky Transportation Center Research Report

District 6 has had a lingering problem of low cylinder-strengths. This report describes, in detail, an ensuing investigation which incorporated the use of identical materials of concretes used in District 6 and analyses of cylinder data, in situ concrete cores, and laboratory mixtures. The investigation revealed that a high percent of the in situ concrete is sound and reliable, and that aggregate type and (or) air content were not the cause for the low cylinder-strengths. The quality of making, storing, and curing the cylinders were the reasons for low-strength.

Freeze-And-Thaw Of Concretes And Aggregates, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents. The effects of air entrainment upon freeze-thaw resistance were demonstrated.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with popouts in concrete were monitored and are presented along with accompanying theoretical considerations.

Voidless Concrete Mixtures For Bridge Decks, Assaf S. Rahal

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable material -- thus producing a no-void concrete. It was adjudged that a water-cement ratio of 0.244 would be practical for hydration of the cement. Several polymeric materials, asphalts, and oils were used to replace the excess mixing water. Success was achieved using two latexes and one epoxy. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.

Construction, Protection And Maintenance Of Concrete Bridge Decks, Ronald D. Hughes, James H. Havens

Kentucky Transportation Center Research Report

This report presents an historical account of deterioration in reinforced concrete bridge decks. Preventative maintenance treatments to both new and in-service decks are discussed. Repair methods are included. The major forms of deterioration are listed and causative mechanisms are discussed. Potential design and construction remedies are presented for consideration.

Durability Of Traffic Paint On Portland Cement Concrete Pavements, Assaf S. Rahal

Kentucky Transportation Center Research Report

Performance of a series of transverse lines applied to a relatively new concrete pavement, utilizing primes and pretreatments, is reported. The report includes descriptions of the location of test lines and types of paint and pretreatments, performance histories, and analysis of results. Chlorinated rubber, epoxy, and urethane paints were the most durable. Neither pretreatment nor the use of primes significantly increased durability.

Concrete Color Variations Observed In Specimens Made From 12 Type 1 Portland Cements, Milton Evans Jr.

Kentucky Transportation Center Research Report

No abstract provided.

A Study Of The Effect Of Blended Coarse Aggregate On Air-Entrained Concrete Progress Report 3, S. T. Collier

Kentucky Transportation Center Research Report

The purpose of this investigetion was to study the durability characteristics of a river gravel, used as coarse aggregate for concrete, with respect to four major fractions separated in accordance to their general mineralogical classification. This aggregate was from the same stock of Ohio River gravel that was used in earlier phases of this Project reported in 1947.

Since this gravel consisted of several rock types varying in mineralogic constituents, it was conceivable that poor performance could possibly be attributed to some undesirable fraction or fractions, rather than to the aggregate as a whole. The separation of this aggregate was …

Study Of The Effect Of Blended Coarse Aggregate On Air Entrained Concrete Second Progress Report, Kentucky Highway Materials Research Laboratory

Kentucky Transportation Center Research Report

When the first progress report on this study of blended aggregate was prepared in January, 1947, only three of the nine groups of samples in Series I had completed the durability tests, and specimens in four of the seven groups composing Series II had not even been prepared. In contrast, at the present all samples in Series I have completed the durability tests thus concluding the results pertaining to Ohio River gravel from Louisville, and specimens in three groups of Series II (applicable to glacial gravel) have finished the durability tests. Further than that, several additional groups of samples which …