On the first screen of Concrete-Works (see page 48), the general inputs screen, the user starts by choosing the closest geographic location available to the placement location, the date of placement, and the time of placement. On the next screen, typical structural shapes are presented and the user selects the shape that most closely matches the application and the boundary conditions (for example, is there water, soil, or air on the outside of the element?).

The user picks the mixture proportions on the next series of screens. Several tabs allow the concrete to be designed according to ACI 211. The chemistry of the cement, and type of coarse and fine aggregate are defined on these screens. Choose a default average or check the box to modify cement composition according to your mill sheet

Next, the user defines the placement temperatures, ice addition, formwork type, formwork color, formwork stripping times, and other construction-related inputs. Wood, steel, insulated, and lined formwork are all possible formwork types that the user can select.

On the next few screens, the user defines the environmental conditions associated with the concrete placement: air temperatures, cloud cover, relative humidity, and solar radiation values are required for accurate predictions. To start, historical average data for the time and day of placement will be generated, but the user can override these values should more specific data be available. The user can view graphs of each of the environmental variables.

The next screen displays checks of the most important input values. Input values are compared to practical ranges and unreasonable values are flagged in red, while normal inputs are flagged in green. This user-friendly feature ensures that no mistakes or unreasonable assumptions have been made with the inputs.

The next screen produces the results in a multitude of formats: text, graph, or animated. The maximum concrete temperature, the minimum concrete temperature, the ambient temperature, and the maximum temperature difference are all displayed. The user can get estimates of the strength development over time if the parameters that uniquely define the strength-maturity relationship are input. The temperature distribution in the cross section can also be animated versus time.

Currently, ConcreteWorks is being beta tested and specified in some TxDOT offices. The results from several large projects under construction in central Texas have shown that the software can predict temperatures within 10% of the measured field results. Updates to the software will be added as work progresses and will be posted at the Web site, www.texasconcreteworks.com. Contact Jennifer Moore (EIT) at Jmoore5@dot.state.tx.us for additional information.

— Jon Poole and Kyle Riding are civil engineering Ph.D. candidates at the University of Texas at Austin. Ralph A. Browne, P.E. is the North Tarrant Area engineer (North Fort Worth) with the Texas Department of Transportation; and Dr. Anton Schindler, P.E., Ph.D. is the Gottlieb assistant professor of civil engineering at Auburn University, Ala.