Bearing Pads Pressure Grouting (15!12!10)

MOCK UP & TRIAL MIX FOR THE (BEARING PAD) PROCEDURES (PRESSURE PUMP METHOD) DATE : 15th DEC 2010 Structural Repairs S/B decided to have another mock up by using pressure pump instead of the flowable method carried out last week since the result of the contact surface of the grout was not fully contact. Mortifications had been done which learnt from the previous lesson. They changed it by using the hand pump and replaced the thin plastic sheet with the wooden plate and added bracing every 200mm as shown. The pressure pump was connect to the inlet and the space and gap shall filled and overflow at the outlet (nose feeding) at the both end.

Inlet

Outlet (nose feeding)

Bracing

Equipments and tools for the pressure pump method. Structural Repairs had delivered they hand pump and cone for the setting out at 2pm.

Hand Pump and Cone

Pressured Indicator and electrical mixer

Tighten the pipe to the connector to cone

Mix ratio with 4.2 liter per 25kg of grout for flowable design mix then mix with the low speed drill

After mixing, stir the grout slowly and lightly with the rod for few seconds to release any entrapped air and pour immediately.

Apply oil to the cube mould

Prepared 6 nos cube with 50mm X 50mm for 7days and 28 days

Using hand pump for transfer the grout to the inlet. Hold it in the position

Knock on the wooden plate to determined the flow and release the entrapped air bubble until the grout over flow

OBSERVATION: Observation at the 18th Dec morning for the 2nd prototype’s outcome Then mould opened and then a result was shown at the picture below:

Large area of air trapped at the left hand side of the outlet. It might caused by the finish level of the top formwork was not level. The reversed air trapped at the highest point by it self leveling after the overflow during the grouting time.

Minor air void (2-5mm) found at the surface of the finishing

PRECAUTIONS & PREVENTIVES 1. Mix then mix with the low speed drill less than 500 rmp 2. After mixing, stir the grout slowly and lightly with the rod for few seconds to release any entrapped air 3. Leveling the top steel plate during grouting 4. Seal all gaps in formwork. 5. Provide sufficient nose feeding to prevent air entrapped

TEST CUBE Test cube for trial mix on 22th Dec 10 3pm. The results were satisfaction

Average Cube strength at 7 days: (68.16+52.04+72.96)÷ 3=64.39 N/mm² > 48 N/mm² ---OK