The Joint Transportation Research Program serves as a vehicle for INDOT collaboration with higher education institutions and industry in Indiana to facilitate innovation that results in continuous improvement in the planning, design, construction, operation, management and economic efficiency of the Indiana transportation infrastructure. https://engineering.purdue.edu/JTRP/index_html Published reports of the Joint Transportation Research Program are available at: http://docs.lib.purdue.edu/jtrp/ NOTICEThe contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views and policies of the Indiana Department of Transportation or the Federal Highway Administration. The report does not constitute a standard, specification or regulation. AbstractThe main objective of this project was to evaluate the effects of using aggregate produced from crushed concrete pavement as a replacement for natural (virgin) coarse aggregate in pavement mixtures. A total of ten different concrete mixtures containing recycled concrete aggregate (RCA) were designed to meet the requirements of Indiana Department of Transportation (INDOT) specifications. These included three different RCA replacement levels (30%, 50% and 100% by weight of the natural coarse aggregate) and two different cementitious systems (plain system -Type I portland cement only and fly ash system -80% of Type I portland cement and 20% of ASTM C 618 Class C fly ash). The scope of the project included the evaluation and comparison of several properties of RCA and natural aggregates, evaluation and analysis of the effects of RCA on concrete properties, and modification of aggregate gradations and mixture composition in an attempt to improve the properties of RCA concrete.All ten mixtures were first produced in the laboratory (trial batches) and were subsequently reproduced in the commercial ready-mixed concrete plant. Each mixture produced in the ready-mixed plant was used to prepare several types of specimens for laboratory testing. The tests performed on fresh concrete included determination of slump and entrained air content. The mechanical properties of the hardened concrete were assessed by conducting compressive strength, flexural strength, modulus of elasticity and Poisson's ratio tests.Concrete durability was assessed using a wide array of measurements, including: rapid chloride permeability (RCP), rapid chloride migration (RCM), electrical impedance spectroscopy (EIS), surface resistivity, free shrinkage, water absorption test, freeze-thaw resistance and scaling resistance.The test results indicated that the properties of plain (no fly ash) concrete mixtures with 30% RCA as coarse aggregate were very comparable to (in some cases even better than) those of the control concrete (0% RCA). Although mixtures with 50% RCA showed a reduction in durability and mechanical properties of up to 36%, the test results still met INDOT's specificatio...

There is a growing trend to replace the traditional ingredients of concrete pavement mixtures with more sustainable materials from a perspective of both the cost of raw materials and the carbon dioxide footprint. The availability of quality natural aggregates, which make up about 70% to 80% of concrete (by volume), is becoming more limited because of environmental restrictions on quarrying operations and longer hauling distances. The other major concern is disposal of old concrete pavements, which unless used as fill or base material for construction of new roadways, will have to be placed in the landfills. In this study, recycled concrete aggregates (RCA) obtained from crushing old concrete pavement were used as coarse aggregates at 0%, 30%, 50%, and 100% replacement levels (by mass) for natural virgin aggregates (NVA). Concrete mixtures were designed and produced to meet the concrete pavement requirements for air content, slump, and flexural strength stipulated by the Indiana Department of Transportation. All concrete mixtures were produced with 18.5% to 20.0% of the cement replaced (by mass) with ASTM C618 Class C fly ash. The physical and mechanical testing involved evaluation of slump, air content, and development of both flexural and compressive strengths. In addition, durability was assessed with the freeze–thaw test, scaling test, rapid chloride permeability (RCP) test, and non–steady state migration test. The most advantageous dosages for replacing NVA with RCA for concrete pavements were found to be 50%, on the basis of fresh concrete properties and the results of strength and durability tests. The applicability of electrical impedance spectroscopy for quick performance appraisal is presented on the basis of the experimental relationship between the RCP charge and bulk resistance of concrete.

tributed to the dramatic increase in 1-day and 3-day strengths but also can contribute to higher amounts of CH in the concrete.• The sulfates also have increased to counteract set problems that can occur with finer cements and more readily available aluminates.A survey of concrete pavements across Indiana revealed that no pavements less than 40 years old from the two southern districts showed this distress, except in more recently placed patches. These districts not only experience a less harsh freeze-thaw (FT) environment but also use lower amounts of deicers. Other evidence from field and laboratory analysis of existing concrete pavements includes the following:• The pavement base drained well at the mid-panel of most pavements but was reduced at the joints for over half the pavements, with the most severe joint deterioration associated with the slowest drainage.• None of the concrete had a measured air void system that met all the criteria recommended for FT durable concrete, but the air void systems were better at the mid-panel than at the joints. Infilling and lining of the entrained air voids with ettringite and some Friedel's salt was more common near the joints and could account for the reduced air void system. The FT testing did not correlate directly with the air void parameters, but generally mid-panel samples did test as more durable than joints.• The presence of unhydrated cement grains suggested that the concrete at the joint face was not always fully cured.• One pavement section that did not have fly ash had worse deterioration than the panels nearby that had fly ash.• Calcium hydroxide was more noticeable in the concrete from joints with severe deterioration. Concrete Pavement Joint DeteriorationJoint transportation research program IntroductionConcrete pavements are an important part of our national infrastructure. In recent years the number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in INDOT specifications, pavement materials and design, construction practices, and deicing materials were examined and related to the durability of concrete at the joints of existing pavements. Cores were retrieved and examined from the joints and mid-panel of 11 pavement sections that represented different materials, ages, construction, deicer exposure, and levels of deterioration, from non-deteriorated concrete to concrete with severe deterioration at the joints. FindingsSeveral variables were identified that influence the durability of concrete at the joints: use of fly ash, joint sealer type, saw cut configurations, water-to-cementitious ratio (w/cm), 7-day flexural strength acceptance criteria, minimum cement content, tie bar spacing and size, target percentage air, and minimum percentage air before failure.The physical properties and chemistry of cements have changed over the years. The fineness has increased for INDOT cements as well as cements used across the country.• The amount of C 3 S has increased, while the amount of...

Concrete pavements located in cold climates have been experiencing premature joint deterioration. Entrapment of moisture in the joints saturates the surrounding concrete, rendering it susceptible to freeze-thaw damage. To identify and to isolate the variables that might be causing this localized deterioration, concrete cores were obtained from deteriorated and non-deteriorated sections of US 35, SR 38, and SR 3, located near Indianapolis, IN, and I-94, located near Michigan City, IN, USA. The visual evaluation of the condition of the pavement revealed that the drainage of the joints contributes significantly to their performance. Specifically, all deteriorated joint core holes drained poorly when compared with well-performing joint core holes or mid-panel joint core holes. Hardened air void parameters were determined following the procedure described in ASTM C457 and results for cores from deteriorated and non-deteriorated regions of the pavements were compared. The chemical and microstructural changes occurring in concrete were investigated using scanning electron microscope. Concrete panels with poor values of spacing factor and specific surface area were more prone to premature joint deterioration. Visual observation of coring sites on I-94 showed that unsealed joints performed better than sealed joints.

Many different spray-on compounds are available for curing concrete, including newer products that are intended to address the environmental concerns associated with high volatile organic compound (VOC) contents. A laboratory study was conducted to examine the effectiveness of different types of curing compounds in retaining water for hydration, promoting concrete strength, and reducing permeability, relative to classic curing techniques such as plastic sheeting and ponding and relative to the use of no curing treatment. Comparisons of moisture loss, compressive strength, permeability, and capillary porosity were made for samples representing three high-VOC curing compounds, three low-VOC curing compounds, water curing, and plastic-sheet curing, and for samples with no curing treatment after 3 days and 28 days of curing. The performance of the six compounds tested varied greatly, but none of the compounds performed as well as the samples cured with water or plastic sheeting. All compounds performed better than samples with no curing treatment.