1. PHS Name:___________
Concrete Temperature & Hardening Lab Partner: ___________
Use sentences – grammar to be checked.
Problem: Is the hardening of cement due to simple dehydration or to a chemical reaction? Why/not?
Hypothesis: I think the hardening of cement is: ___________________________________________.
Material:
• pH paper • 100 mL of quick set cement
• 2styrofoam cups, small, big • 1 alcohol thermometer
• 50 mL of water • 1 scoopula
Procedure:(Executing the protocol, gathering the data or observations)
1. Using the teacher’s premarked cup, measure 100 mL of cement powder into the big cup.
2. Using the teacher’s premarked cup,measure 50 mL of water into the little cup.
3. Using the thermometer, determine the temperature of the water to 1 decimal place.
4. Using the pH paper, determine the pH of the water.
5. Add slowly sufficient water and stir the mixture thoroughly using the scoopula.
6. At the same time, using the thermometer, measure the maximum temperature of the
water/cement mixture.
7. Using the pH paper, determine the pH of the water/cement mixture.
8. Centerthe smaller cup full of water in the middle of your water/cement mixture.
9. Cover your cup with a sheet of paper and label with your name.
10. Record all you data.
11. Label your Styrofoam cup.
12. Clean up your lab site.
Data: Make a chart of your collected data.
Analysis of Data:
1. Calculate the temperature change.
2. Calculate the change in pH.

2. Discussion:
1.) Is the hardening of cement due to a physical change or chemical reaction? What data supports
your response?
2.) Given the fact that the reaction began with the addition of water, is it preferable to keep the
cement moist or to promote its dehydration during the curing? Why?
3.) Is there a distinction between heat and temperature? Explain.
4.) What could the effect of excessive temperature be on the hardening of cement? (Hint: What will
happen to the water in the mix?)
5.) Cement powder can be finely ground. The smaller the particle size, the greater the total surface, of all
the particles combined. The increase of total surface area will result in a faster reaction time.In
your opinion, is it better for the particles of cement to be large or small, if we want a fast reaction?
Why?
Conclusion: Answer the problem.
Sources of Error: