Early-Age Design

Software tools such as HIPERPAV (High PERformance concrete PAVing) III and CRSI PowerPave are currently available to engineers for the analysis of CRCP early-age behavior. These tools can be used as a way to fine-tune designs under given site-specific construction scenarios. These tools may be also helpful in developing specifications based on locally available materials and construction procedures. These tools can be used for the following:

  • Determining optimum paving times.
  • Evaluating mixture changes that could be used to either reduce or increase the heat of hydration.
  • Optimizing mixture designs as they interact with expected paving conditions.
  • Determining the window for sawing operations of the longitudinal joints.
  • Determining when and what additional curing may be needed.
  • Estimating opening times for traffic. Recent advancements in concrete maturity and on site weather monitoring now allow this to be done in real time (FHWA SmartCure).
  • Reducing the risk of thermal shock cracking.
  • Determining when it is safe to stop or start paving due to adverse weather.

HIPERPAV III

Developed under sponsorship of the FHWA, this software represents computerized design and construction guidelines for optimization the early-age behavior of CRCP.(1)Computer-Based Guidelines for Concrete Pavements (FHWA-HRT-04-121) In HIPERPAV III, the crack spacing, crack width, steel stress, and bond development length are predicted as a function of design, materials, environment, and construction factors, and then evaluated in terms of predefined design thresholds.

A sophisticated model for the prediction of concrete pavement temperature is used at the core of the software. The predicted pavement temperature is used for both the prediction of strength and stress development in the concrete. The cracking prediction is based on the CRCP-8 model. Originating from findings under NCHRP research project 1-15, the CRCP-8 model has since been extensively validated through laboratory and field testing.(2)Design of CRCP for Highways (NCHRP Project 1-15)(3)Mechanistic Analysis of CRCP Considering Material Characteristics, Variability, and Fatigue (FHWA/TX-92+1169-2)

Go the the HIPERPAV III website.

PowerPave

Developed by CRSI, PowerPave is similar to HIPERPAV II, and is also based on the CRCP-8 model. However, pavement temperature is not predicted but it is rather an input to the software.

References   [ + ]