modern day curing

2. Curing CMUs
Heat of Hydration
Low Pressure Steam Kiln
Autoclaving

3. Configuration and design of curing
chambers
• Sample Layout – Individual Atmosphere Chambers with
moving rack system

4. Configuration and design of curing
chambers
• Sample layout – Single Atmosphere large room
system

5. SUBJECTS TO BE COVERED
1). STEAM CONDITIONS
2). CURING CYCLE
3). KILN DESIGN
4). BOILER SELECTION

8. CONTROLLED CONDITIONS
OF STEAM
1). Quantity
2). Quality
3). Velocity

9. Quantity - Have the required boiler
capacity to produce enough steam to
complete the curing cycle.
Quality - Saturated steam is a quality
steam, having the correct amount of heat
& moisture present.
Velocity - Correct piping to induce
steam evenly into kilns for equal
distribution.

17. Rate of Temperature Rise of
Block Should be About:
60 deg. F or 33.3 deg. C/ hr.
5.5deg.C /10 min.or 33.3deg.C/hr

19. EQUILIBRIUM
TEMPERATURE WILL VARY
WITH:
1). Type of Block
2). Material
3). Kiln Size
4). Rate of Temperature
Rise
5). Weather
6). Kiln Insulation

25. AFTER SHUTTING OFF STEAM, BLOCK SHOULD BE ALLOWED
TO SOAK 6 TO 8 HOURS.
The soaking period is as important as the steam time. The longer the
units are allowed to soak the better will be the final results. As long
as the air in the kiln is not disturbed, the humidity of the kiln increases
as the temperature decreases, because the moisture content is relatively
constant. An accelerated curing condition is maintained in the kiln
during the entire time the temperature is falling to 70 degrees (21.11c).
Therefore, the longer soaking period is extended, the greater the
compressive strength of the block.

26. DETERMINATION OF
BOILER LOAD
1). Individual kiln requirements
2). Number of kilns being operated simultaneously
3). Plant heating requirements
4). Miscellaneous loads

38. In conclusion it must be remembered that the
proper curing of concrete masonry is a processing
problem and not a heating problem. The proper
installation of a efficient curing system is the job of a
person thoroughly familiar with the thermodynamic
properties of steam and air, and also familiar with
boilers, preheating and water treatment.