The Cement Pour

So the day has arrived when we are finally casting our molds.  Our morning began by unwrapping our molds and clearing them of any moisture and sand that may have accumulated.  Jasmine checked again that the molds were level and we kept a sharp eye out for the truck. Jasmine sprayed the molds with a release agent to help with the de-molding. The students could only observe at this stage for practical and safety reasons as the PH level of the particular concrete mix we used was 11.  Jasmine, the concrete company employees and our concrete techs were in charge of the pour.  The concrete was tinted to add visual interest and difference to the traditional cement benches that will  be installed. As the concrete was poured in, Jasmine tapped the sides of the molds to release any air bubbles that might be lurking in the mix and potentially take away detail.   Once the concrete was in place, it was smoothed and left to partially set up.  When the surface was firm enough, we covered the forms with burlap sacks and wet them in order to keep an even level of moisture as the concrete set.  When we were done, we wrapped them up in a tarp to keep them dark and poly sheeting to protect them from the elements.

Prepping the molds

We have prepped the molds!  Jasmine brought the molds to our school so that we could get them ready for the pour the next day.  We helped her unload the van and the materials/equipment we would need and brought the molds into an art room that didn't have a class in it at the moment.  The students then proceeded to clean the molds with damp cloths: a meticulous job that ensures nothing will interfere with the detail we hope to get with the concrete. They then tightened the bolts on the mother mold ensuring it was ready to support the weight of the cement. Students cut burlap into wide strips that will eventually be used to keep our freshly poured concrete moist.  Meanwhile, Jasmine's sandbox was built and filled with sand - thank you to our fabulous maintenance and grounds staff!  We put the sandbox in the fenced area behind the technology education rooms as planned and walked over the molds.  Jasmine had previously tested the molds to see what we would get and below is an example of the incredible detail from the "lunch" locker designs.

 Next Jasmine and her crew began the task of suspending rebar inside the molds for extra strength. They used wires, clamps and wood to keep the rebar steady and away from an edge.  Next we moved the molds to the sandbox and then began the delicate job of ensuring they were level.  Afterwards we used the shop vac to clean out any sand that got into the molds in the process and covered the molds for the night.

We were all excited to see what would happen in the morning.  The cement truck was scheduled for first thing and we were as ready as we could be.