• And DowelCAD 2.0, a software program created collaboratively for optimization of dowel bar design. The software also allows engineers to determine joint responses to varying dowel sizes or investigate the impact of various alternate dowel bar configurations and shapes.

Moving Ahead

Keeping pace with web-based technology also means meeting the growing demand among smartphone users. ACPA has developed a number of iPhone and iPad apps, and continues to monitor use of other platforms, including Android, with an eye on further development to meet demand. The current list of ACPA’s iPhone and iPad apps includes:

Area and Volume Calculator: An app that allows users to quickly calculate plan area and volume of material based on a pavement or subbase/subgrade layer’s thickness, width and length.

Evaporation Rate Calculator: This app uses the evaporation rate equations in Paul Uno’s ACI Materials Journal article, “Plastic Shrinkage Cracking and Evaporation Formulas,” (July/August 1998). The equations are based on the popular evaporation rate nomograph from ACI 305R, Weather Concreting. Using this tool, users can quickly calculate the evaporation rate at hourly intervals based on concrete temperature, air temperature, ambient relative humidity and wind velocity.

Concrete Mixture Proportioner: Provides a method of proportioning a concrete mixture using the absolute volume method in substantial conformance with ACI 211.1-91, “Standard Practice for Selecting Proportions for Normal, Heavyweight and Mass Concrete.”

Maximum Joint Space Calculator: Allows users to calculate joint spacing in jointed plain (unreinforced) concrete pavement.

Staking Interval Calculator: Calculates the rate of change of a vertical curve and, based on this value, provides maximum staking interval recommendations.

Subgrade Resilient Modulus Calculator: Based on the conversion factors included in NCHRP Report 128, “Evaluation of AASHTO Interim Guide for the Design of Pavement Structures,” this tool allows users to quickly estimate the Subgrade Resilient Modulus (MRSG) from either a California Bearing Ration (CBR) or Resistance Value (R-value) measurement.

Joint Noise Estimator: An app based on the work of acoustics expert Dr. Paul Donavan, Sc.D., a senior scientist at Illingworth and Rodkin. This tool allows designers to estimate the impact of various joint geometries and condition on the overall tire-pavement noise level. It may also be used to guide pavement maintenance efforts in terms of the noise-related benefits attainable from sealing joints.

These mobile applications are available in Apple’s iTunes App Store store (http://www.store.apple.com/) for a nominal fee. Users of iPhones and iPads who click on the iTunes App Store link on the ACPA App Library site will be taken directly to an application purchase site; all other users will be directed to landing pages that describe the product and include ordering information.

For additional information about the ACPA web apps and links to software programs, contact the author at 847.423.8706 or rrodden@acpa.org. v