Wednesday 22 April 2015
Transverse Beam Pressure Grouting
The final installation and repair of chipping aggregate was approves in the image below. The chipping aggregate will sere as temperature control of the grout. This was approved in 17.April.2015
Before grouting I submitted a revised Non Conformance Reply to the Consultant for further review of the machine and grout that will be used in the grouting procedure. The requirements should be the grouting machine should have a valve to indicate the controlled pressure which is not more than 15 Psi and a grouting strength of 60Mpa.
We are using a PG Grout by Emix. A trial mix was conducted before to get the accurate result of the grout strength. 4 sets of 3 cubes 100x100x100mm was prepared for the test of
1 day(early strength)
3 days (de moulding sttrength)
7 days &
28 days.
It was found out that the 60MPa can be achieved at 3 days early strength of the cube.
Form works was installed so that it can withstand the 20 psi pressure.
1 inlet was prepared in the form works located at bottom location of the affected area. and 2 outlet was prepared 1 in the upper right corner and 1 at the top corner of the defect area. This is to ensure that all areas will be grouted.
A simple indication that the grout was fully occupied the area was the outlet must a have a consistent flow of grout coming out .
Once the grout is flowing consistently in the outlet close it and pump again to continue grouting until the upper outlet flows out the grout.
The machine used was a new purchase. Checking the model, brochure and test certificates of the machine should be valid in the last 3 months or maximum of 12 months.
The PG Grout bag was used. We need a flowable type of grout to be inserted to our machine. This is to ensure that grout can reach all the remote places and hard places to reach by making the mix flowable.
1 Grout bag was mixed in 4.5 Liters of water. Check the manufacturers instruction for correct dosage
The machine was pumped first with water to test if the machine was working properly. A constant flow of water during pumping need to be ensured.
Once the test is done. Mix the the grout with water with a mechanical mixer
Ensure the pressure gauge is working
The grouting batch should be finished within the span of 30 minutes or else the grout will start to set.
Summary: the duration of the repair took 2 weeks to complete. which includes investigation, hacking and preparation of documents. Of course the preparation of the location and safety requirements should be satisfied first.
It was a headache!! hahaha,, have a nice day
Friday 17 April 2015
Transverse Beam Repairing with Pressure Grouting
The Damages (10 April 2015)
Removing of Loose concrete and installation of chipping aggregates for Grouting. Chipping Concrete will help to reduce the heat pressure of the grout during the grouting period. 10-15 MPa pressure will be used to grout the defected area (14 April 2015)
It was found out that the degree of damages was extended not visible to the eyes due to small opening. It was decided to hack the area again about 200-300mm and 250mm deep
The extent of the damages was determined and installation of appropriate amount of chipping aggregate or granite aggregate was installed. 1 inlet and two outlet of the pressure grout will be installed in the formworks to ensure the grout will travel all the void spaces and leave no air bubbles to ensure all grouting will be completed (17 April 2015)
My next post will be the grouting itself. on 21 April 2015
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