NCCCO Concrete Pump (CPO) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Allowable bearing capacity

The maximum soil pressure a ground surface can support without excessive settlement, used to size outrigger pads so calculated bearing pressure stays below it with a safety margin.

Outrigger float sizing

Pad area is chosen so total outrigger load divided by effective contact area stays under the soil's allowable bearing capacity; soft fill needs larger mats or cribbing.

One-call utility locate

The free service (811 in the US) that marks underground utilities before excavation or setup; outriggers and stabilizers must stay outside the marked tolerance zone.

Boom load chart

The manufacturer's table giving allowable boom tip load and reach for each boom length, radius, and outrigger configuration; it is not a lifting rating.

Exclusion zone at the pump

The area around the pump, hopper, and discharge point restricted to the operator, signal person, and necessary crew during pumping to prevent injury from blowouts or moving parts.

Maximum wind speed for boom

The manufacturer's limit above which the boom must be lowered or stowed; gusts near the limit require stopping the pour and securing the boom.

Rated output versus actual

Published pump output in cubic meters per hour is measured under ideal conditions; actual output drops with line length, lift, elbow count, and low slump.

Maximum concrete pressure

The highest pressure in bar the pump can develop at the outlet; it must exceed calculated line resistance from distance, elevation, elbows, and slump.

Safety clamp or whip check

A restraining device fitted at each pipe coupling and hose connection that limits travel if a coupling separates under pressure, protecting nearby workers.

Hopper grate

A heavy grid over the hopper that blocks oversize material and prevents workers from reaching the agitator or auger; it must be intact whenever the pump runs.

Accumulator hazard

A hydraulic accumulator stores pressurized fluid after shutdown; pressure must be bled per the manual before any fitting is opened or maintenance begins.

S-valve and wear ring

The valve that switches concrete flow between the two cylinders; a worn wear ring causes lost output, higher pressure, and concrete leaking past the valve.

Boom pin inspection

Checking boom and outrigger pins for wear, looseness, and missing retainers during pre-use inspection; failed pins can drop a boom section.

Line priming

Coating the inside of the pipeline with grout, slurry, or a sponge pig before concrete is pumped, preventing segregation and blockage at the first restriction.

Free-fall limit for concrete

Concrete should not drop more than roughly one to one and a half meters into a form; greater falls segregate coarse aggregate from mortar and weaken the placement.

Layer thickness for placement

Placing concrete in horizontal layers of about 300 to 500 millimeters and consolidating each layer with a vibrator prevents voids and cold joints.

Adding water at the pump

Adding water to increase slump on site raises the water/cement ratio and lowers strength; it requires approval from the producer and engineer.

Blockage response

Stop pumping, reverse briefly at low pressure, then relieve pressure before opening any coupling; personnel must stay out of line with the pipe end.

Vertical pipe anchoring

Vertical runs need secure anchoring and a trap or blow-back arrangement so concrete does not free-fall back down the line when pumping stops.

Signal person authority

One agreed signal method is used, and the operator stops immediately on any unclear signal or on a stop signal from any worker on the site.

Air-blowing the line

Cleaning the pipeline with a sponge ball driven by compressed air; the line must be anchored and restrained, and no one may stand at the discharge end.

Hopper entrapment hazard

Reaching into the hopper can pull a worker into the agitator; only the grate and a proper tool are used, and the pump is locked out for hopper work.

Stored energy in a blocked line

A blocked or pressurized pipeline holds energy like a compressed spring; pressure must be relieved before any coupling is opened and personnel kept clear.

Power line contact response

If the boom contacts an energized line, the operator stays in the cab and warns others away until the utility confirms de-energization, unless fire forces evacuation.

Wet concrete chemical burns

Wet concrete is highly alkaline and can cause serious skin burns; gloves, boots, and prompt washing are required, and eye protection prevents splash injury.

Washout containment

Washout water is often a regulated discharge; it is contained in a lined pit or tank and never released to a storm drain or waterway.

Lockout/tagout on pumps

Isolating hydraulic and electrical energy, bleeding accumulators, and verifying zero energy before maintenance; required for hopper, valve, and hydraulic work.

Daily lubrication points

Slew ring, boom pins, outrigger pins, and hopper shaft are greased at the manual's interval; missed grease is a leading cause of pin and bearing failure.

Hydraulic overheating causes

High oil temperature often traces to a clogged cooler, low oil level, or a stuck relief valve; oil level, filter restriction, and temperature are checked daily.

Blockage causes list

Low slump, oversized aggregate, poor priming, too many elbows, a collapsed hose, or long pumping pauses that let concrete stiffen in the line.

Clearing a line blockage

Stop, reverse at low pressure, and if that fails, relieve pressure and open the line from the pump end one restrained joint at a time.

Boom failure emergency procedure

If the boom cannot retract or hydraulics fail, stop, secure the area, and follow the manufacturer's emergency lowering procedure rather than improvising with the boom aloft.