Laying foundations with compressed air

Establishing solid, reliable foundations is crucial for the structural integrity and longevity of nearly all constructions. Helical piles, impact-driven piles, drilled shafts, caissons, piers, and earth-stabilised columns all go some way to transferring the structure’s load to the earth, and provide a steadfast base on which the structure can be built.

A fundamental ‘deep-foundation’ technology, reinforced concrete piles are commonplace on most commercial building sites. The piles are driven or poured in place, effectively transferring the load from the structure to a deep layer of soil or bedrock. Once installed, the piles must be trimmed to the required level to allow the above-ground construction to continue. Compressed air plays a major role in this process.

Removing what can sometimes be up to several metres of excess foundation, pile trimming can be laborious and time consuming. Where access is available, large excavator-mounted hammers can be used to trim the piles, saving time and labour. However, at most construction sites, there are a number of activities happening concurrently, so this level of access is usually not permitted. Furthermore, such powerful excavator-mounted hammers have the potential to damage the pile or compromise its structural integrity, causing costly and time-consuming repair or replacement.

According to TrimPile director Danny Allen, handheld, air-driven jackhammering provides many advantages over the excavator-mounted hammer method of pile trimming. “Operators have more control with a handheld jackhammer, and are less likely to damage the functional portion of the pile,” he says. “Jackhammers are also more manoeuvrable and not limited by site-access issues.”

TrimPile sought compressed air advice from Sullair Australia. “We needed gear that was designed and manufactured to withstand the hot, humid and dusty conditions experienced on Australia’s construction sites,” says Allen. “You can’t afford to have breakdowns on site, so we needed a reliable compressed-air solution.”

Initially, Sullair Australia supplied TrimPile with one 375DPQ rotary screw portable compressor (which delivers compressed air at a rate of 375 cfm at 100 psig), as well as four 60-pound Sullair MPB60 paving breaker jackhammers. The air compressor is equipped with a five-outlet manifold so all four jackhammers can be operated simultaneously along with an air-driven concrete saw. “We’re delighted with the performance of the Sullair compressor,” says Allen. “It has plenty of ‘grunt’, which allows us to run multiple tools at the same time.”

The team was given the opportunity to ‘road test’ the Sullair jackhammers on site. “We jumped at the chance to test out the Sullair gear in a ‘real’ situation,” says Allen. “The Sullair MPB60s performed exceptionally, with no freeze-ups.”

Sullair Victorian product manager Daryl Davis says, “Unlike other jackhammers, the MPB60s don’t require additional oil lubrication, which saves time and maintenance. Additional savings can be realised thanks to its efficient compressed air use. The unit’s direct-impact piston design minimises air consumption without compromising performance.”

The jackhammers are quiet. “The piston impacts directly on the steel shank rather than a tappet, which reduces noise levels dramatically,” says Davis. “The silenced units are handy for smaller concrete-breaking applications like those in built-up or residential areas.”

The jackhammer’s ergonomic design was a real benefit for TrimPile. “The minimal vibration and reduced kickback means less fatigue for the operator,” says Allen. “The unit’s combination of manoeuvrability and hard-hitting power is also a real feature. It allows us to complete jobs sooner, while maximising the operator’s comfort.”

Following TrimPile’s initial purchases, the concrete-breaking expert has gone on to acquire five more Sullair jackhammers. “I reckon I’ve used just about every make of air compressor and jackhammer over the years,” says Allen. “The Sullair gear is built tough. It’s right up there with the best.”