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HPC-09 v6 - SMARTh Bed Heating

Objective Technology announces HPC-09 v6 SMARTh Bed Heating. The technology builds on the advances reported in News Bulletin "Your Data is a Gold Mine", and can help with Meeting Curing Deadlines under challenging conditions, Improve Quality by Reducing Risk of Cracking and Save Money.

It is challenging to Cure Concrete Slabs with short Target Curing Times and Low Ambient Temperatures.

You may use Bed Heat all the Time and as high a Pouring Temperature as possible. The problem with this is High Temperature Gradients across the Slab. The Temperature Gradients may be reduced by using No Bed Heat and a Higher Pouring Temperature, combined with some Bed Heat: But how much Bed Heat, and what Pouring Temperature?

HPC-09 v6 SMARTh Bed Heating takes care of this scenario and helps meet the Target Curing Time with Minimum Pouring Temperature and Bed Heat, and thus supports LEAN & Sustainable Manufacturing Principles! Minimizing Pouring Temperature and Bed Heat reduces Cross Sectional Temperature Difference and thereby Reduces Risk of both Micro-Cracking and larger Cracks. In short: Quality is Improved!

The Technology Challenge is to do this in a way that still allows Detection of Discrepancies! Blindly Ramping Bed Heat Up / Down will undermine the ability to Detect of Discrepancies...

All Graphs below show Slab Cross Sectional Temperatures (Tdiff) over a HD320 Slab (12.6" Hollow Core) when Ambient Temperature is 15 deg C (50 F), Target Strength is 35 MPa (5076 Psi) and the Target Curing Time of 07:00 is met, but with different methods. Ts = Pouring Temperature.

HPC-09 v6 SMARTh Bed Heating: Calculated Ts: 25 C (77 F) Total Calculated Bed Heat Time: 00:25, Max Tdiff: 17 deg C (62.6 F).

We see that we with SMARTh Bed Heating has achieved a very Low Cross Sectional Temperature Difference of 17 deg C, and also used a moderate Pouring Temperature and only Total 25 minutes of Bed Heating! The Low Pouring and Cross Sectional Temperature Difference Reduces Risk of both Micro-Cracking and larger Cracks.

You think you can do better? What about using No Bed Heat and just increase the Pouring Temperature? Let's investigate:

Bed Heat: 00:00, Ts: 29.4 C (84.9 F), Max Tdiff: 21 deg C (70 F).

We see that to cure the Slab in 07:00 hours (without Bed Heat), we need to increase the Pouring Temperature to 29.4 Deg C. This creates a large Temperature Difference between the Slab Surface and the Ambient Temperature, and drives the Cross Sectional Temperature Difference up to 20 deg C. This is 3 deg C higher than what the HPC-09 v6 SMARTh Bed Heating achieved!

Depending on what fuels the Bed Heating and the Heating of Aggregates & Water (to increase the Pouring Temperature), we may also Save Energy using the SMARTh Bed Heating.

Finally, we investigate what happens if we use Bed Heating for the entire curing time:

Bed Heat: 07:00, Ts: 23.5 C (74.3 F), Max Tdiff: 24 deg C (75 F).

We notice that Maximum Temperature Difference across the Slab Exceeds the Max Legal Tdiff of 20 deg C (68 F). According to NS-EN-13369 & FDOT, we are outside the legal Tdiff, and the Large Tdiff increases the chance of Cracking.