Implementing Epoxy Injection in Concrete Overlaid Bridge Decks

SPR-4320Concrete overlays have proven to be an effective maintenance treatment as they slow de-icing chemical and water penetration into the original deck surface. Typically, due to vibration, structural flexibility, and a weak bond between the concrete overlay and deck concrete (potentially because of poor construction), de-bonding develops at the boundary between the original deck and the overlay. This de-bonding creates voids, providing a reservoir for chloride-laden water to fill after it penetrates cracks in the surface. Displacing this liquid solution and filling these cracks with epoxy helps reduce freeze/thaw cycling and reduces spalling. The epoxy material protects the bridge deck from moisture and helps support the overlay and prevent it from failing under traffic loads. This leads to an extension of the asset life span and life cycle cost benefit increase. Overall, the bridge infrastructure performance improves significantly with greater mobility and less traffic interruptions due to bridge repairs on roadway infrastructures. Epoxy injections helps extend the service life of bridge decks and reduces the need for emergency bridge deck patching and thus improves the safety of road users. Epoxy injection has been added to INDOT\u2019s Maintenance Work Performance Standards during the course of this study

Determining Optimal Traffic Opening Time Through Concrete Strength Monitoring: Wireless Sensing [Summary]

SPR-4513Construction and concrete production procedures are time sensitive and fast paced. As such, it is crucial to monitor the strength of concrete in real-time. Existing concrete strength testing methods, such as traditional hydraulic compression method specified by ASTM C 39 and the maturity method specified by ASTM C 1074, can be inaccurate, labor intensive, and cumbersome for field implementation

Determining Optimal Traffic Opening Time Through Concrete Strength Monitoring: Wireless Sensing

SPR-4513Construction and concrete production are time-sensitive and fast-paced; as such, it is crucial to monitor the in-place strength development of concrete structures in real-time. Existing concrete strength testing methods, such as the traditional hydraulic compression method specified by ASTM C 39 and the maturity method specified by ASTM C 1074, are labor-intensive, time consuming, and difficult to implement in the field. INDOT\u2019s previous research (SPR-4210) on the electromechanical impedance (EMI) technique has established its feasibility for monitoring in-situ concrete strength to determine the optimal traffic opening time. However, limitations of the data acquisition and communication systems have significantly hindered the technology\u2019s adoption for practical applications. Furthermore, the packaging of piezoelectric sensor needs to be improved to enable robust performance and better signal quality

Developing Customized NRCS Unit Hydrographs (Finley UHs) for Ungauged Watersheds in Indiana

SPR-4433The Natural Resources Conservation Service (NRCS, formerly the Soil Conservation Service, SCS) unit hydrograph (UH) is one of the most commonly used synthetic UH methods for hydrologic modeling and engineering design all over the world. However, previous studies have shown that the application of the NRCS UH method for some ungauged watersheds in the state of Indiana produced unrealistic flood predictions for both the peak discharge and the time to peak. The objective of this work is to customize the NRCS UH by analyzing the role of its two key parameters, namely, the peak rate factor (PRF) and the lag time, in creating the runoff hydrograph. Based on 120 rainfall-runoff events collected from 30 small watersheds in Indiana over the past two decades, the observed UHs are derived and the corresponding PRF and lag time are extracted. The observed UHs in Indiana show that the mean value of PRF is 371, which is lower than the standard PRF of 484, and the NRCS lag time equation tends to underestimate the \u201ctrue\u201d lag time. Moreover, a multiple linear regression method, especially the stepwise selection technique, is employed to relate the NRCS UH parameters to the most appropriate geomorphic attributes extracted from the study watersheds. Both the statewide and regional regression models show that the main channel slope is a major factor in determining the PRF and lag time. A customized Indiana unit hydrograph, referred as Finley UH to honor David Finley who inspired this study, is derived with updated parameters and the Gamma function. Validation results show that the Finley UH provides more reliable and accurate predictions in terms of the peak discharge and the time to peak than the original NRCS UH for the watersheds in Indiana

GIS-Based Geotechnical Database for Collaborative GIS

SPR-4616INDOT spends at least 8 million dollars annually on geotechnical site investigations, not including the amounts spent by contractors. The laborious and costly job of data collection in geotechnical practice requires the efficient storing and organizing of this valuable data to develop correlations and trends in spatially varying geotechnical data. INDOT currently uses gINT software for managing geotechnical data and ArcGIS for storing boring logs and geotechnical reports. The INDOT geotechnical office is pursuing means to improve the efficiency of their operations by developing a GIS-based geotechnical database for secure storage, easy retrieval, and flexible sharing of geotechnical data to enhance decision making. SPR-4616 is the first step towards the development of a geotechnical data management system in which important decisions on the components and structure of the database were made. The report presents a detailed conceptual layout for the development of a geotechnical database following an object-oriented programming approach. The report discusses in detail the geotechnical applications, the field, laboratory, and verification tests that will be included in the database. The geotechnical variables required to perform the engineering analysis in designing specific applications are logically linked with the geotechnical tests from which they are obtained. Lastly, a detailed layout of the proposed database structure and a user workflow example is provided in the report and can serve as a guide during the development of the database system

Large Culvert Inspection Procedures: Guidelines for INDOT

SPR-4432Within the state of Indiana, there are approximately 9,000 structures with unsupported span lengths that range from 4 ft to 20ft that the Indiana Department of Transportation (INDOT) is responsible for maintaining. These structures are referred to as large culverts by INDOT. The agency recognized the need to improve culvert inspection procedures so that inspection data that is collected can provide essential information to asset engineers who make decisions regarding culvert management. The purpose of the project described in this report was to identify best practices for the inspection and management of these structures to develop guidelines that optimize the resources allocated for the maintenance and inspection of large culvert structures. This study found that standardizing the inspection process and evaluation criteria for inspection will positively impact the overall performance of the inventory of these structures. A proposed large culvert inspection manual accompanies this report and provides a detailed guide for large culvert inspection

Development of a Multiple Water Course Joint Probability Analysis Procedure for Indiana Watersheds

SPR-4430The design of hydraulic structures located near a confluence of two streams must take into consideration the flows from both of the streams. A hydraulic structure located on a small tributary that drains into a large river immediately downstream is not just affected by the flow in the tributary, but also by the backwater flow from the downstream river. Currently INDOT uses a tabular summary (Table 1.1 and Table 7.3 in the HEC-22 manual) of joint probabilities of coincident flows in designing hydraulic structures at confluences. However, the source of the table is unknown, and the tabular summary provides coincidental flows for only 1% and 10% probabilities, and thus it cannot be used directly for other probabilities. This study analyzed the interdependence of flows in mainstream and tributary and then developed a Gumbel-Hougard Copula-based procedure for estimating joint probabilities for confluences in Indiana. The study found that the mainstream and tributary streamflow are significantly correlated with Kendall\u2019s Tau varying generally ranging from 0.5 to 0.8. Furthermore, the Kendall\u2019s Tau, which is the key parameter for Gumbel-Hougard Copula, was found to be significantly related to drainage area ratio (DAR). Regression-based equations between DAR and \u3c4 are used as a basis to relate DAR to joint probabilities at confluences. The study also found that the currently used tabular summary (Table 1.1 and Table 7.3 in HEC-22 manual) resulted in significantly conservative design estimates and therefore overdesigned structures

Improving Scaling Resistance of Pavement Concrete Using Titanium Dioxide (TiO2) and Nanosilica

SPR-4336This project focused on the evaluation of the influence of nanoadditives on the hydration kinetics, mechanical properties, and durability of concretes with and without supplementary cementitious materials (SCMs). The types of nanomaterials used in the course of this study included nano-titanium dioxide (nano-TiO2) and two forms of nanosilica. A series of experimental tasks, including fabrication, curing, and conditioning of specimens, microstructure analysis, mechanical strength testing, and durability testing were conducted in the laboratory. Based on experimental results, it can be concluded that the addition of nanoparticles can accelerate the early-age hydration process of cementitious pastes, especially those containing fly ash and cured at low temperatures. Both the compressive and flexural strength of mortars and concretes were also enhanced by the addition of nanoparticles. In addition, incorporation of nanoparticles reduced the total amount and connectivity of pores present in concretes. That resulted in lowering the water permeability of concretes, regardless of the cementitious systems and curing temperatures used. The resistance of concretes to freeze-thaw cycles and scaling was also improved by the addition of nanoparticles, especially those containing fly ash. However, an excess of nanoparticles additions may reduce the scaling resistance of concretes

Development of Volumetric Acceptance and Percent Within Limits (PWL) and Criteria for Stone Metrix Asphalt (SMA) Mixtures in Indiana

SPR-4325SMA is designed based on SMA volumetric properties in terms of air voids content (Va), voids in the mineral aggregate (VMA), and adequate stone-on-stone contact. For construction quality assurance (QA) purposes, INDOT currently accepts SMAs based on aggregate gradation and asphalt binder content. Thus, there is a discrepancy between SMA design criteria and construction acceptance. To better align design and construction, it is necessary to consider SMA volumetric properties in the use of QA. For HMA mixtures, INDOT has already transitioned from volumetric QA acceptance procedures to PWL. Today, SMA still uses adjustment points, which are not based on robust statistics, for QA acceptance

Synthesis Study on Employing Snowplow Driving Simulators in Training

SPR-4651Departments of Transportation (DOTs) need to mobilize workers under harsh weather conditions for winter operations. Traditional snowplow driver training at INDOT is usually conducted annually before the snow season; therefore, it does not replicate the conditions which drivers will be exposed to during winter operations. To this point, some state DOTs have incorporated simulators in their snowplow driver training. Despite this raised interest, few studies have (1) surveyed other state DOTs about the use of this equipment in winter operations driver training, or (2) provided a systematic consideration of all factors involved in the decision to use driving simulators in snowplow driver training. To fill these gaps, the present study synthesizes information from previous literature, revises current information from INDOT, and surveys other state DOTs to identify the benefits and challenges of driving simulators for snowplow driver training. A mixed methods approach was utilized including a review of current INDOT practices, interviews with stakeholders, a survey of other state DOTs, and results from a pilot training. Based on the findings, the researchers recommend that INDOT continues to explore the use of driving simulators for training purposes in addition to the yearly snowplow driver training, due the ability to reinforce learning in a safe environment. Moreover, the research team suggests the following areas for further research: evaluating optimal simulator \u201cseat time,\u201d peer learning in simulator training, and the impact of experience level and work assignment in the perception of driving simulator training effectiveness