Conbextra Deep Pour - Technical Details and Specifications

Product Overview

Conbextra Deep Pour is a flowable, precision cementitious grout specifically engineered for large volume and deep pouring applications. It is supplied as a ready-to-use dry powder that, when mixed with controlled amounts of clean water, produces a free-flowing precision grout suitable for demanding grouting requirements where standard products are insufficient.

Key Applications

Conbextra Deep Pour is designed for grouting gap applications ranging from a minimum of 20mm to 500mm in thickness, making it particularly suitable for grout depths exceeding 125mm. It serves as an alternative grouting solution when Conbextra GP or other standard products cannot accommodate project requirements. The product is formulated to minimize segregation and bleeding for deep grout pours, ensuring reliable performance in demanding installation scenarios.

Composition and Properties

Material Composition

Conbextra Deep Pour is a dual shrinkage compensated (non-shrink) cementitious grout composed of:

• Portland cements
• Graded fillers
• Chemical additives that impart controlled expansion in both plastic (Class A) and hardened (Class C) states

The filler grading minimizes segregation and bleeding over a wide range of application consistencies. The maximum filler aggregate size contained in Conbextra Deep Pour is 5mm.

Physical Properties

Property	Value
Fresh Wet Density	2200 kg/m³ (depending on consistency used)
Minimum Thickness	20mm
Maximum Thickness	500mm
Color	Charcoal grey (mixed)

Mechanical Strength Properties

Compressive Strength (AS 1478.2:2005)

Consistency	Water Addition (L/20kg)	1 Day (MPa)	7 Days (MPa)	28 Days (MPa)
Plastic	2.4 - 2.6	10	45	65
Flowable	2.6 - 2.8	5	42	60

Flexural Strength (Modulus of Rupture)

• 7 Days: 5.0 MPa
• 28 Days: 7.5 MPa

Indirect Tensile Strength

• 7 Days: 2.5 MPa
• 28 Days: 4.0 MPa

Setting Time Properties

Setting times are measured according to AS 1012.18:1996:

• Initial Set: 6.5 hours
• Final Set: 9.0 hours

According to ASTM C953:2017 testing:

• Initial Setting Time: 390 minutes
• Final Setting Time: 440 minutes

Water Requirements and Yield

The water content is critical for achieving desired consistency levels:

Required Consistency	Litres of Water per 20kg Bag	Yield (litres of mixed material)
Plastic	2.4 - 2.6	10.0
Flowable	2.6 - 2.8	10.0

Each 20kg bag produces approximately 10.0 litres of mixed material. Allowance should be made for wastage when estimating quantities required.

Flow Characteristics

Conbextra Deep Pour demonstrates excellent initial flow and flow retention:

• Flow Trough Test Result: 500mm

Flow properties vary based on gap depth and hydrostatic head:

Gap Depth (mm)	Flowable 100mm Head (mm)	Flowable 250mm Head (mm)
30	1500	3000
40	2200	3000+
50	3000	3000+

Standards Compliance

Conbextra Deep Pour meets multiple international standards:

• Non-shrink according to ASTM C1107:2020 - Specification standard for grout materials
• AS 1478.2-2005 Appendix E - Early Volume Change
• AS 1478.2-2005 Table 4.1.2.2 - Consistency
• Rapid Mortar Bar Test (RTA T363) - Non-reactive
• SAA MP20.3-1977 - Class A & Class C

ASTM C1107:2020 Test Results

Test Method	Standard	Result
Flow Consistency	ASTM C939:2016a	>145%
Setting Time (Initial:Final)	ASTM C953:2017	390 mins : 440 mins
Change in Height at Early Age	ASTM C827:2016	+0.29%
Height Change of Hardened Grout (Moist Cure)	ASTM C1090:2015	+0.3% (1, 3, 14, 28 days and 28+28 days in air)
Compressive Strength	ASTM C109:2020b	13.8 N/mm² (1 day), 39.4 N/mm² (3 days), 51.2 N/mm² (7 days), 63.8 N/mm² (28 days)

Key Advantages

• Non-metallic, dual expansion system compensates for shrinkage in both plastic (Class A) and hardened (Class C) states
• Non-shrink - according to ASTM C1107:2020
• Excellent initial flow and flow retention suitable for large volume pours
• High ultimate strength and low permeability ensure durability of hardened grout
• Hydrogen-free gaseous expansion
• Chloride free
• Suitable for pumping or pouring into position
• RCS (Respirable Crystalline Silica) Hazard Free - classified as hazard-free for RCS in accordance with the Australian Inventory of Industrial Chemicals; contains <0.1% RCS

Mixing Requirements

Mixing Method

A forced-action mixer is essential:

• Mix for 3 to 5 minutes at slow speed (400/500 rpm)
• Use appropriate equipment such as a 120/140mm helical mixing paddle fitted to a heavy-duty 1600W mixer
• Always add powder to water (not vice versa)
• Ensure smooth, even consistency is obtained

Larger Volume Mixing

For larger quantities, a high shear vane mixer is recommended. Do not use a colloidal impeller mixer. Machine mixing capacity and labor availability must be adequate to enable continuous grouting operations, which may require a holding tank with gentle agitation.

Placing and Application

Formwork Requirements

• Minimum gap for pouring: 25mm
• Formwork must be leakproof (using foam rubber strip or construction silicone sealant)
• Unrestrained surface area must be kept to minimum
• Gap width between perimeter formwork and plate edge should not exceed 150mm on the pouring side and 50mm on the opposite side
• No gap at flank sides

Pre-soaking

Pre-soaking the formed grouting area with clean water helps ensure good adhesion and improves flow:

• Fill area with clean water for minimum 2 hours before grouting
• Drain or vacuum any free water immediately before grouting
• Blow out bolt holes and pockets

Placing Technique

• One-sided pouring from one side of the void only to eliminate air entrapment
• Maintain continuous grout flow throughout operation
• Ensure sufficient grout is available before starting
• Pour grout across the shortest distance of travel to maintain continuous grout front

Pumping

Where large volumes must be placed, Conbextra Deep Pour may be pumped using:

• Heavy duty diaphragm pumps (recommended)
• Screw feed and piston pumps
• Maximum aggregate size for pumping: 5.0mm

Supply and Storage

Packaging Options

Conbextra Deep Pour is supplied in two formats:

• 20kg bags (Product Code: FC501070-20KG) - Standard projects
• 1000kg bulk bags (Product Code: FC501070-1000KG) - Made to Order; minimum order quantities apply

Shelf Life

• 18 months from date of manufacture if kept in original, unopened bags
• Product should be stored in appropriate conditions
• Do not use if lumps are present or loss of workability is experienced

Temperature Considerations

Low Temperature Working

When air or contact surface temperatures are 5°C or below:

• Use warm water (30-40°C) to accelerate strength development
• For ambient temperatures below 10°C, use flowable consistency
• Maintain formwork in place for at least 36 hours
• Adopt normal winter working precautions for cementitious materials

High Temperature Working

At ambient temperatures above 35°C:

• Store mixed grout in shade
• Use cool water (below 20°C) for mixing

Curing

On completion of grouting operations, exposed areas should be thoroughly cured using:

• Concure curing membrane
• Continuous water application
• Wet hessian

Design Considerations

Long narrow grouting sections should be avoided. Pours should be arranged to achieve a length-to-minimum-thickness ratio of not more than 20:1.

References

• [1] Fosroc_Conbextra_Deep_Pour_TDS.pdf