Concrete and Masonry OverviewMore than the majority of other construction trades, concrete and masonry work require a strict accounting of a large number of variables, time being the most crucial. Once cement is mixed with sand, aggregate and water, there is a limited amount of time to pour, work and finish concrete. But, time is not the only variable. A miscalculated mix ratio can result in weak, brittle or porous concrete. A curing temperature that is too cold can destroy concrete before it matures. Excessively hot mix temperatures reduce the compressive strength of concrete. The adhesion matrix of concrete does not develop if concrete is not mixed thoroughly enough. A concrete mix with too much water lacks cohesion and cures soft and weak. Mistakes in concrete and masonry work are invariably more costly than mistakes made in other construction trades. The consequences of not having the right tools and machines for a concrete project can be extremely costly and time consuming. Once concrete cures, repairing a mistake becomes a new project all-together. Accounting for large number of variables in concrete and masonry work requires having the requisite tools to control the mix, make the pour and finish the job. There are six fundamental types of concrete and masonry tools, machines and equipment: cutting and drilling; finishing equipment; mixing equipment; mixing and placing machines; surface preparation machines; and miscellaneous equipment.
How do you know which machine is right for the job?
There are two types of construction-related concrete work: load-bearing and flat. Load-bearing concrete work includes: footers/foundations; retaining walls; structural walls; and columns. The emphasis on load-bearing concrete work is usually compressive strength. Flatwork requires an emphasis on tensile strength and includes things like garage floors, patios, elevated decks and sidewalks.
The requisite tools and machines for load-bearing and flatwork are often different. However, there are basic tools and equipment fundamental to both types. The list includes: drills, saws, grinders, and mixers (unless the concrete is delivered).
The requisite tools for masonry work differ from those of strict concrete work. Drills and grinders, for example, are not essential to masonry work. Like load-bearing and flatwork, however, there are requisite tools and equipment.
Equipment specific to load-bearing work:
- Concrete Vibrator - Regardless of the construction concrete job, if compressive and tensile strength are priorities, the less water in a mix the better. However, the less water in a mix, the more likely it is air will get trapped in the poured mix. A vibrator is the best means of preventing this likelihood. Even a pencil vibrator does an exponentially better job than jamming a shovel handle into the mix over-and-over and beating the sides of the forms with a hammer.
- Rebar Bender - While a rebar bender is helpful on a flatwork job because it prevents waste, the reinforcement bar can simply be cut to length and tied. Load-concrete, on the other hand, requires rebar bends the majority of the time. The only concrete job more difficult than trying to cut rebar without a grinder or cutter is trying to bend it by hand, particularly if it is #3 or larger. It is not worth the time spent nor money saved.
Equipment specific to flatwork:
- Trowels - Trying level flatwork without a trowel is an exercise in futility. Some concrete men are satisfied using a small section of lumber, but it makes for tiresome, inexact work. A trowel is a necessity when finishing concrete.
- Bull Float - While a concrete man may be able to get away with using a two-by-four when finishing a sidewalk -- it can be layed across the forms and jigged back-and-forth -- a flatwork project that is wider than three or four feet requires a bull float if any degree of exactness expected.
- Power Trowel - While some concrete men prefer to use a fresno to finish the last step of a flatwork project, a power trowel requires less experience to use and the finish is, arguably, just as precise and aesthetically appealing.
- Joiners, Edgers and Jitterbugs - used to curve the edges of a flatwork job or indent a crease through the slab in -- order to create a weak joint where the concrete will crack first if the tensile strength of a slab fails when the ground shifts or settles beneath it, -- joiners, edgers and jitterbugs are used to add the final touches to flatwork.
Equipment specific to load-bearing work:
- Brick or Tile Saw - Cutting tile by hand and breaking breaks with a chisel are possible, but the cuts are seldom as precises as those generated by a saw. If aesthetics are an objective of a brick or tile project, and appearance typically is when masonry work is concerned, a saw is essential.
- Mixing Drill or Mortar Mixer - A concrete mixer is inappropriate for mixing mortar. The weight of a mixing drill or mortar mixer -- their small sizes -- make them easy to move around a project. Unlike concrete, mixing volume is not a concern when working with mortar. The rate at which a mason places mortar is much slower than the rate at which concrete is poured. So, mixing a small amount at a time -- so as to prevent it from curing before it is placed -- is good form.
Common Types of Concrete and Masonry Equipment
Cutting and Drilling
Today's concrete forms are, almost exclusively, fastened with drills and screws. A concrete worker uses a drill as much as any other tool or piece of equipment. Concrete and masonry men are as selective with regard to saws as they are with respect to drills, some, more-so. There are considerably more different types of saws than there are types of drills.
Finish work is an inexact science, but a walk behind power trowel can make blemishes in flatwork disappear. For those concrete workers that want both perfect the level on a flatwork project and to give concrete a unique and beautiful finish, diamond grinders are a must.
Other Considerations When Renting Concrete and Masonry Equipment
Does the Project Require Rebar?
As examples, if the project does not require reinforcing bar, there is less of a need for a grinder on the job and no need for a bender or cutter. If the job is for load-bearing concrete -- which almost always requires rebar, and the equipment associated with reinforcing bar -- there is probably no need for an edger, a joiner, a jitter bug, a power trowel or a bull float. But, there is likely a need for a vibrator.
Will the Concrete Be Load-Bearing or Flatwork?
Masonry work may not require many of the same tools as load-bearing or flatwork, but there are just as many that are required. A brick or tile saw is the primary requisite.