Iowa EDI Claim and Reporting Compliance Handbook, July 2001

The purpose of this handbook is to provide the user with an educational and process reference guide. This is a guide that the reader may utilize to learn Iowa’s reporting and compliance system and also as a handy day-to-day document that may be referred to thereby assisting that individual and/or entity to understand and maintain compliance with Iowa Workers’ Compensation statutes and rules and the requirements required therein.

Youth Rights and Responsibilities Handbook. 2004

This handbook is designed to provide you with general information regarding your rights and the effect and operation of the law upon you as a minor. It is not intended to be legal advice. Should you find yourself in a situation with a specific legal problem, you should obtain competent legal advice from attorney

Field Evaluation of Quality Management Concrete, MLR-97-3, 1998

Quality management concrete allows the contractor to develop the mix design for the portland cement concrete. This research was initiated to gain knowledge about contractor mix designs. An experiment was done to determine the variation in cylinders, beams, and cores that could be used to test the strength of the contractor's mix. In addition, the contractor's cylinder strengths and gradations were analyzed for statistical stability and process capability. This research supports the following conclusions: (1) The mold type used to cast the concrete cylinders had an effect on the compressive strength of the concrete. The 4.5-in. by 9-in. (11.43-cm by 22.86-cm) cylinders had lower strength at a 95% confidence interval than the 4-in. by 8-in. (10.16-cm by 20.32-cm) and 6-in. by 12-in. (15.24-cm by 30.48-cm) cylinders. (2) The low vibration consolidation effort had the lowest strength of the three consolidation efforts. In particular, an interaction occurred between the low vibration effort and the 4.5-in. by 9-in. (11.43-cm by 22.86-cm) mold. This interaction produced very low compressive strengths when compared with the other consolidation efforts. (3) A correlation of 0.64 R-squared was found between the 28 day cylinder and 28 day compressive strengths. (4) The compressive strength results of the process control testing were not in statistical control. The aggregate gradations were mostly in statistical control. The gradation process was capable of meeting specification requirements. However, many of the sieves were off target. (5) The fineness modulus of the aggregate gradations did not correlate well with the strength of the concrete. However, this is not surprising considering that the gradation tests and the strength tests did not represent the same material. In addition, the concrete still has many other variables that will affect its strength that were not controlled.

Embankment Quality and Assessment of Moisture Control Implementation, TR-677, 2016

A specification for contractor moisture quality control (QC) in roadway embankment construction has been in use for approximately 10 years in Iowa on about 190 projects. The use of this QC specification and the development of the soils certification program for the Iowa Department of Transportation (DOT) originated from Iowa Highway Research Board (IHRB) embankment quality research projects. Since this research, the Iowa DOT has applied compaction with moisture control on most embankment work under pavements. This study set out to independently evaluate the actual quality of compaction using the current specifications. Results show that Proctor tests conducted by Iowa State University (ISU) using representative material obtained from each test section where field testing was conducted had optimum moisture contents and maximum dry densities that are different from what was selected by the Iowa DOT for QC/quality assurance (QA) testing. Comparisons between the measured and selected values showed a standard error of 2.9 lb/ft3 for maximum dry density and 2.1% for optimum moisture content. The difference in optimum moisture content was as high as 4% and the difference in maximum dry density was as high as 6.5 lb/ft3 . The difference at most test locations, however, were within the allowable variation suggested in AASHTO T 99 for test results between different laboratories. The ISU testing results showed higher rates of data outside of the target limits specified based on the available contractor QC data for cohesive materials. Also, during construction observations, wet fill materials were often observed. Several test points indicated that materials were placed and accepted at wet of the target moisture contents. The statistical analysis results indicate that the results obtained from this study showed improvements over results from previous embankment quality research projects (TR-401 Phases I through III and TR-492) in terms of the percentage of data that fell within the specification limits. Although there was evidence of improvement, QC/QA results are not consistently meeting the target limits/values. Recommendations are provided in this report for Iowa DOT consideration with three proposed options for improvements to the current specifications. Option 1 provides enhancements to current specifications in terms of material-dependent control limits, training, sampling, and process control. Option 2 addresses development of alternative specifications that incorporate dynamic cone penetrometer or light weight deflectometer testing into QC/QA. Option 3 addresses incorporating calibrated intelligent compaction measurements into QC/QA.