HA104 COMPLIANT BEDDING MORTARS AND THE MOST EFFECTIVE METHOD OF APPLICATION.
In this article, we discuss the concept of HA104 compliant bedding mortars, their uses and the most efficient application methods, that ensure the highest level of strength, longevity and time saved.
Highways ironworks take a huge pounding from extreme volumes of traffic every day including heavy goods vehicles (HGVs). There are many concrete and bedding mortars available on the market, but only a few that can stand up to the large volumes of traffic on busy strategic networks.
The majority of products used to reinstate or install ironworks are specialist water-based cementitious systems. On many busy networks and other heavily trafficked roads, it is a standard requirement to use an HA104 approved material. HA104 systems are generally formulated from water-based polyester technology that can achieve a high strength (see details below) within 3 hours.
HA104 bedding mortars must meet the below requirements:
- Reach 30 N/mm² compressive strength within 3 hours
- Reach 5 N/mm² tensile strength within 3 hours
- 15 minutes workability time
These bedding mortar systems are available as a trowel or flowable options, provide an incredible bond to ironworks and can be guaranteed to a much higher level.
Below we focus on an HA104 compliant installation that guarantees durability and long term performance.
Read more below.
FRAME INSTALLATION WITH ADJUSTABLE LEVELING BOLTS (Meon Recommended Install)
In this application, we will be focusing on using a highway compliant ironwork frame with adjustable nylon levelling bolts and Meon HardMaster HA104 compliant bedding mortar concrete.
Initially remove all failed reinstatement materials as recommended within SROH which defines the width of trim back dependent on the reinstatement materials used.
Once the area to be reinstated has been broken out, is clean, sound and secure, then the ironwork frame can be placed onto the prepared chamber. To save costs when using HA104 self-levelling mortars, installers can create a bund or shutter around the frame.
USING HARDMASTER W621 SELF LEVELING HA140 COMPLIANT BEDDING MORTAR WITH ADJUSTABLE LEVELING BOLTS.
Once the frame has been set down, place a straight edge on the surrounding surface, over the top of the frame to determine its height in relation to the surrounding finished surface level. The frame top edge must be flush with the carriageway surface.
STEP BY STEP GUIDE – HOW TO APPLY
Following on from the instructions above… nylon inserts are located under the frame to ensure the minimum of Depth of the bedding material (15mm) is achieved. It is crucial to make sure the frame is flush with the surrounding surface.
To create a dam on the internal face of the frame, use either a tight-fitting foam strip (as pictured) or pack HardMaster W620 HA104 Bedding Mortar into the opening. Ensure all gaps are filled and tightly packed to prevent any flowable mortar escaping (step 3). Refer to HardMaster W620 technical data for mixing instructions.
Thoroughly mix the HardMaster W621 with a mechanical whisk for at least 3 mins. Apply immediately by pouring the mixture in at the highest point. The mixture will self-level around the frame, pushing out any air. Keep pouring so the mixture raises above the framework flange and covers the 20mm nylon shoulders on the adjustable bolts. (see diagram – step 1 & 3)
ABOUT MEON HARDMASTER HA104 CONCRETES
TROWELLABLE BEDDING MORTAR
HardMaster W620 is a high strength bedding mortar which provides exceptional performance in wet conditions. It has a guaranteed cure as it is a two-component product and can achieve strengths of 40N/mm² in 3 hours. Typical applications include the bedding of inspection chamber frames and covers.
Mortar complies with Department of Transport HD 27/04 Design Manual for Roads and Bridges HA104/09 and NRA MCDRW Vol 1 Clause 501.17.
FLOWABLE BEDDING MORTAR
OTHER INSTALLATION TECHNIQUES
PART BED APPLICATION
For highways ironwork frames that don’t incorporate or have the capability for a levelling system, use HardMaster W620 Ha104 compliant bedding mortar to support the frame. Place pyramids on each corner of the chamber where the 4 comers of the frame will be placed and gently lower the frame into place. Using a non-metal mallet, tap down so the frame is level with carriageway surface level.
Once this has been done revert back to STEP 2 in the “STEP BY STEP GUIDE” above, by tightly fitting either a foam filler strip or the remainder of the HardMaster W620 into the gap on the internal face of the frame.
FULL BED APPLICATION
Once again for frames that don’t incorporate a levelling system, frames can be installed using a full bed of HardMaster W620 trowellable bedding mortar. Simply place the mixed material around the top of the chamber at a suitable depth, where the frame will be laid, making sure you have sufficient material and that there are no gaps. Gently lower the frame into position and tap down using a non-metal mallet, so that the top of the frame is level with carriageway surface level.
Once the material has set (after 20 mins) the backfill material can be placed. Depending on the desired finish, either PatchMaster H576 Permanent asphalt repair or HardMaster W615 backfill concrete can be used.
REINSTATEMENT AND SURFACE REPAIR MANAGER
If you have any questions about the HardMaster range, or reinstatement & surface repair in general, then please get in touch with me today. Email me on email@example.com