Development and Evaluation of a Portable Device for Measuring Curling and Warping in Concrete Pavements, 2016

Portland cement concrete (PCC) pavement undergoes repeated environmental load-related deflection resulting from temperature and moisture variations across pavement depth. This has been recognized as resulting in PCC pavement curling and warping since the mid-1920s. Slab curvature can be further magnified under repeated traffic loads and may ultimately lead to fatigue failures, including top-down and bottom-up transverse, longitudinal, and corner cracking. It is therefore significant to measure the “true” degree of curling and warping in PCC pavements, not only for quality control (QC) and quality assurance (QA) purposes, but also for better understanding of its relationship to long-term pavement performance. Although several approaches and devices—including linear variable differential transducers (LVDTs), digital indicators, and some profilers—have been proposed for measuring curling and warping, their application in the field is subject to cost, inconvenience, and complexity of operation. This research therefore explores developing an economical and simple device for measuring curling and warping in concrete pavements with accuracy comparable to or better than existing methodologies. Technical requirements were identified to establish assessment criteria for development, and field tests were conducted to modify the device to further enhancement. The finalized device is about 12 inches in height and 18 pounds in weight, and its manufacturing cost is just $320. Detailed development procedures and evaluation results for the new curling and warping measuring device are presented and discussed, with a focus on achieving reliable curling and warping measurements in a cost effective manner.

Maintenance of Traffic for Innovative Geometric Design Work Zones, 2015

Currently there are no guidelines within the Manual on Uniform Traffic Control Devices (MUTCD) on construction phasing and maintenance of traffic (MOT) for retrofit construction and maintenance projects involving innovative geometric designs. The research presented in this report addressed this gap in existing knowledge by investigating the state of the practice of construction phasing and MOT for several types of innovative geometric designs including the roundabout, single point urban interchange (SPUI), diverging diamond interchange (DDI), restricted-crossing left turn (RCUT), median U-turn (MUT), and displaced left turn (DLT). This report provides guidelines for transportation practitioners in developing construction phasing and MOT plans for innovative geometric designs. This report includes MOT Phasing Diagrams to assist in the development of MOT strategies for innovative designs. The MOT Phasing Diagrams were developed through a review of literature, survey, interviews with practitioners, and review of plans from innovative geometric design projects. These diagrams are provided as a tool to assist in improving work zone safety and mobility through construction of projects with innovative geometric designs. The aforementioned synthesis of existing knowledge documented existing practices for these types of designs.

Concept Highway Maintenance Vehicle, Final Report, Phase One, 1997

The state Departments of Transportation (DOTs) of Iowa, Michigan, and Minnesota formed a consortium to define and develop the next generation highway maintenance vehicle. The Center for Transportation Research and Education of Iowa State University provided staff support to the concept highway maintenance vehicle project, which focused on winter maintenance activities. Phase I of the three-phase project focused on describing the desirable functions of a concept maintenance vehicle. Phase II will include the development, operation, and evaluation of prototype winter maintenance vehicles. Phase III is envisioned to be a comprehensive fleet evaluation of prototype winter maintenance vehicles. This report covers the activities of Phase I. Phase I included conducting a literature review of materials related to winter highway maintenance activities, identifying ideal capabilities of a winter maintenance vehicle, inviting private sector equipment and technology providers to join the project and commit equipment and expertise for Phase II, and determining the specific equipment and technology to be included on the three prototype vehicles for the winter of 1996-1997. Phase I concluded by establishing that assembling the three prototype vehicles would be beneficial to the project and to the three state DOTs.

Nondestructive Evaluation and Assessment of Concrete Barriers for Defects and Corrosion, 2013

Wiss, Janney, Elstner Associates, Inc. (WJE) evaluated potential nondestructive evaluation (NDE) methodologies that may be effective in 1) identifying internal defects within slip formed concrete barriers and 2) assessing the corrosion condition of barrier dowel bars. The evaluation was requested by the Bridge Maintenance and Inspection Unit of the Iowa Department of Transportation (IaDOT) and the Bureau of Bridges and Structures of the Illinois Department of Transportation (IDOT). The need arose due to instances in each Department’s existing inventory of bridge barriers where internal voids and other defects associated with slip forming construction methods were attributed to poor barrier performance after completion of construction and where, in other barrier walls, unintentional exposure of the dowel bars revealed extensive corrosion-related section loss at previously uninspectable locations, reducing the capacity of the barriers to resist traffic impact loads. WJE trial tested potential NDE techniques on laboratory mock-up samples built with known defects, trial sections of cast-in-place barriers at in-service bridges in Iowa, and slip formed and cast-in-place barrier walls at in-service bridges in Illinois. The work included review of available studies performed by others, field trial testing to assess candidate test methods, verification of the test methods in identifying internal anomalies and dowel bar corrosion, and preparation of this report and nondestructive evaluation guidelines.

Motor Grader Operator Maintenance of Granular Surfaced Roads : Tips from Iowa Operators, 1991

This booklet is a compilation of notes taken during motor grader operators workshops held at some 20 different locations throughout Iowa during the last two years. It is also the advice of 16 experienced motor grader operators and maintenance foremen (from 14 different counties around Iowa), who serve as instructors and assistant instructors at the "MoGo" workshops. The instructors have all said that they learn as much from the operators who attend the workshops as they impart. Motor grader operators from throughout Iowa have shown us new, innovative and better ways of maintaining gravel roads. This booklet is an attempt to pass on some of these "tips" that we have gathered from Iowa operators. It will need to be revised, corrected, and added to based on the advice we get from you, the operators who do the work here in Iowa.

Quantitative Guidelines for Thin Maintenance Surfaces, TR-435, 2003

What follows are the refined guidelines from the Thin Maintenance Surface: Phase II Report. For that report, test sections were created and monitored along with some existing test sections. From the monitoring and evaluation of these test sections, literature reviews, and the experience and knowledge of the authors, the following guidelines were created. More information about thin maintenance surfaces and their uses can be found in the above-mentioned report.

Fast Track and Fast Track II - Cedar Rapids, Iowa, HR-544, Construction Report, 1989

Two lanes of a major four lane arterial street needed to be reconstructed in Cedar Rapids, Iowa. The traffic volumes and difficulty of detouring the traffic necessitated closure for construction be held to an absolute minimum. Closure of the intersections, even for one day, was not politically feasible. Therefore, Fast Track and Fast Track II was specified for the project. Fast Track concrete paving has been used successfully in Iowa since 1986. The mainline portion of the project was specified to be Fast Track and achieved the opening strength of 400 psi in less than twelve hours. The intersections were allowed to be closed between 6 PM and 6 AM. This could occur twice - once to remove the old pavement and place the base and temporary surface and the second time to pave and cure the new concrete. The contractor was able to meet these restrictions. The Fast Track II used in the intersections achieved the opening strength of 350 psi in six to seven hours. Two test sections were selected in the mainline Fast Track and two intersections were chosen to test the Fast Tract II. Both flexural and compression specimens were tested. Pulse velocity tests were conducted on the pavement and test specimens. Maturity curves were developed through monitoring of the temperatures. Correlations were performed between the maturity and pulse velocity and the flexural strengths. The project was successful in establishing the feasibility of construction at night, with no disruption of traffic in the daytime, using fast Track II. Both the Fast Track II pavements were performing well four years after construction.

Development of Evaluation, Rehabilitation, and Strengthening Concepts for Low Volume Bridges, Phase I Progress Report, HR-323, 1990

The primary objective of this project is to develop a design manual that would aid the county or municipal engineer in making structurally sound bridge strengthening or replacement decisions. The contents of this progress report are related only to Phase I of the study and deal primarily with defining the extent of the bridge problem in Iowa. In addition, the types of bridges to which the manual should be directed have been defined.

Load Testing and Load Rating Eight State Highway Bridges in Iowa, 1999

This main report provides a general discussion of the load testing, structural evaluation, and load rating procedures. Specific details for each bridge are provided in individual report sections. Additional supporting information on load testing, analyses, and load rating are also provided in the attached appendices.

Durability and Durability Tests for Paving Asphalt: A State-of-the-Art Report, HR-124, 1969

This special report is prepared to review durability and durability tests for paving asphalt, both in theory and in application. The report summarizes and evaluates factors related to asphalt durability, problems associated with durability study and development of durability tests, important work on durability and practical design implications concerning asphalt durability. It is a state-of-the-art report and a part of the study under HR-124, Development of Laboratory Durability Test for Asphalts.

Iowa Highway Programs, Finances, and Progress, 1951

(a) Iowa has a total of 101,620 miles of rural roads, both primary and secondary. (b) On January 1, 1951, a total of 68,869 miles of these rural roads were surfaced - mostly with gravel and crushed stone. (c) Additional roads are being surfaced at the rate of 2676 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 26.0 per cent from property taxes, 63.5 per cent from road use taxes, 10.5 per cent from Federal aid. (f) Annual income under present laws, available for highway construction, is approximately For primary roads ----------------- $24,000,000 For secondary roads---------------- $41,967,000 (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued. (h) Unobligated available farm to market road funds are rapidly being placed under contract. (i) The letting of highway contracts is increasing rapidly. (j)- Iowa's highway program is estimated to cost $945,000,000 and will require twenty years to build. These are the highlights of Iowa's highway program. The details will follow in succeeding paragraphs.

Iowa Highway Programs, Finances, and Progress, 1952

(a) Iowa has a total of 101,620 miles of rural roads, both primary and secondary. (b) On January 1, 1952, a total of 71,493 miles of these rural roads were surfaced - mostly with gravel and crushed stone. (c) Additional roads are being surfaced at the rate of 2662 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 26.0 per cent from property taxes, 63.5 per cent from road use taxes, 10.5 per cent from Federal aid. (f) Annual income under present laws, available for highway construction, is approximately For primary roads------------------$23,000,000 For secondary roads---------------- 41,967,000 (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued. (h) The surplus of farm to market road funds created during and immediately following the War have now been placed under contract, with only a minimum working balance remaining in the fund. (i) Iowa's highway program was estimated to cost $945,000,000 and to require twenty years to build, by the 1948 Legislative Committee. This estimate would now have to be increased due to price increases and higher required standards. These are the highlights of Iowa's highway program. The details will follow in succeeding paragraphs.

Iowa Highway Program, Finances and Progress, 1954

(a) Iowa has a total of 101,451 miles of rural roads, both primary and secondary. (b) On January 1, l954, a total of 77,024 miles of these rural roads were surfaced - mostly with gravel and crushed stone. This is 5,53l miles greater than on January l, 1952. (c) Additional roads are being surfaced at the rate of 2766 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 25.4 per cent from property taxes and special taxes......................................$29,708,546.67 63.7 per cent from road use taxes.......... 74,581,080.30 10.6 per cent from Federal Aid (1952 Act).. 12,424,000.00 0.3 per cent from miscellaneous receipts.. 287,922.86 ---- ------------- 100.0 $117,001,549.83 (f) Annual income under present laws, available for highway construction, is approximately, For primary roads $29,420,000.00 For secondary roads $44,328,000.00 In 19_3, $7,299,000 of secondary road construction funds was transferred to the maintenance fund. (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued.

Primary Roads and Their Municipal Extensions, 1949

A discussion of several issues related to road construction, including budget, legislation, maintenance, and pending improvements.

Laboratory performance evaluation of CIR-emulsion and its comparison against CIR-foam test results from Phase III, TR-578

Currently, no standard mix design procedure is available for CIR-emulsion in Iowa. The CIR-foam mix design process developed during the previous phase is applied for CIR-emulsion mixtures with varying emulsified asphalt contents. Dynamic modulus test, dynamic creep test, static creep test and raveling test were conducted to evaluate the short- and long-term performance of CIR-emulsion mixtures at various testing temperatures and loading conditions. A potential benefit of this research is a better understanding of CIR-emulsion material properties in comparison with those of CIR-foam material that would allow for the selection of the most appropriate CIR technology and the type and amount of the optimum stabilization material. Dynamic modulus, flow number and flow time of CIR-emulsion mixtures using CSS-1h were generally higher than those of HFMS-2p. Flow number and flow time of CIR-emulsion using RAP materials from Story County was higher than those from Clayton County. Flow number and flow time of CIR-emulsion with 0.5% emulsified asphalt was higher than CIR-emulsion with 1.0% or 1.5%. Raveling loss of CIR-emulsion with 1.5% emulsified was significantly less than those with 0.5% and 1.0%. Test results in terms of dynamic modulus, flow number, flow time and raveling loss of CIR-foam mixtures are generally better than those of CIR-emulsion mixtures. Given the limited RAP sources used for this study, it is recommended that the CIR-emulsion mix design procedure should be validated against several RAP sources and emulsion types.