Vibrations: How Harmful Can These Be for Construction Workers

vibrations how harmful can these be

Every town or urban setup owes its stature to its outstanding infrastructure — buildings, bridges, roads and railways among other structures. Looking at their beauty, it’s hard to think of the difficulty people had in building these super structures.

And it’s even harder to picture how the tasks affect the health of construction workers. Part of the routine of these workers is the use of machines that produce vibrations that are detrimental to their health. Know what are the effects of vibration on the human body and how to prevent them.

 

So, where exactly does vibration come from?

There are two types of vibrations — hand-arm and whole body vibration.

Hand-arm vibration (HAV) is transmitted to your hands and arms while you are operating hand-guided equipment and hand-held power tools. Vibrations that hands and arms feel when holding materials being processed by machines also fall under this category.

construction worker using a jackhammer 

Hand-arm vibration is felt by workers who frequently use jackhammers, grinders, chainsaws, drills, impact wrenches and riveters.

Harmful whole body vibration (WBV), on the other hand, comes from vehicle activity, engine vibration and rough surface conditions or bumpy roads and resistance forces.

These can be amplified by road construction activity, vehicle design, vehicle condition, vehicle suspension systems maintenance, vehicle speed, driver awareness and skills and work organisation can increase or decrease exposure to WBV.

Moreover, things like tool characteristics, work organisation and individual characteristics and skills can increase or decrease exposure to HAV.

 

Types of construction activities that generate vibration

These  construction activities generate vibrations:

Road Construction is done using heavy equipment and machinery.

Machine operators experience vibrations at virtually every stage of the construction process. For starters, the laying of sub grade involves digging up the sub-soil and thoroughly compacting the sub-grade. In this, you use rollers weighing up to 8 tonnes.

These rollers are used to compact different layers. They make rapid humming movements which register as whole body vibrations on the operator.

Machines used in creation of curbs and other concrete materials also produce vibrations.  

worker using a extractor

And when you are installing new valves, pipes, fittings and manholes, you need to drill and do excavation. These drillers and excavators frequently generate a lot  of vibration.  

Moreover, hand-arm vibration is produced in concrete removal, brought about by hammers and jackhammers.and tools used to shape building stones.

stone-chipping tool

But it’s not only in construction site that vibrations can be observed.  Construction workers in quarries also experience both hand-arm and whole body vibrations from pneumatic stone-chipping tools.

With so many activities causing hand-arm and whole body vibration, it’s important to understand how vibrations adversely affect the health of construction workers to minimise so to minimise the impact of such vibration.

 

Side-effects of vibration

HAV and WBV can cause harm if not kept in check.

WBV frequently causes or exacerbates health effects such as lower back pain. A person is likely to have lower back pain because their ligaments get loose due to the repeated shaking. Vibration can also cause mild to acute damage to the back bone and discs.

fallen from ladder

This kind of vibration may also cause motion sickness, damage to bones and reproductive organs, vision or balance impairment, digestion problems, heart conditions and changes in respiratory and endocrine systems.

The risk of having these health problems increases when a worker is exposed to WBV for a long time.  

Another effect of HAV is Vibration-induced white finger (VWF).

VWF is the most common among persons who operate hand-held tools that produce vibrations. Symptoms of VWF become more amplified when exposed to cold.

achy shoulder

Such vibration can cause change muscles, tendons, joints and bones and even impair the nervous system. These effects are collectively referred to as Hand-Arm Vibration Syndrome (HAVS).

 

Common symptoms of HAVS

  • Blanching (whitening) of one or more fingers when exposed to cold;
  • Tingling feeling on the fingers and loss of sensation;
  • Pain and cold sensations in between episodic white finger attacks;
  • Loss of grip strength; and
  • Bone cysts in wrists and fingers.  

These symptoms develop gradually, becoming severe over time. Problem is, HAVS may take up to several years before becoming clinically noticeable.

Overall, vibration induced health conditions develop slowly. You only feel pain in the beginning. But with continued exposure, this develops into an injury or ailment.

 

Ways to minimise the impact of vibrations

Here are some measures to minimise the dangers of vibration:

1. Right choice of equipment 

Use low-vibration equipment and tools.

low-vibration equipment

Using equipment that is for instance not powerful enough or is too small may entail longer time to complete the task. This translates to longer exposure to vibration.

 

2. Proper work practices

Improper use of equipment is one reason ailments develop from vibrations.

With this in mind, familiarise yourself thoroughly with how the equipment should be operated so you it would produce less vibration. Further, limit loads on hands and wrists and ensure you apply the right grip force.

safety construction attire

Always wear the right gloves and clothing. Where possible, make use of suspension systems and jigs to take vibration and weight of equipment away from the operator.

 

3. Regular worker rotation

Rotating workers ensure they get the right break from such exposure to harmful vibrations. They would have enough rest so they need to handle equipment correctly and safely.

The effects of vibration can be prevented or at least contained provided you know how to do it. The above steps are enough to keep workers safe from the impact of vibrations.

The Process of Making Concrete

Let’s face it – a lot of people use the words “concrete” and “cement” interchangeably mistakenly thinking these refer to the same thing.

This couldn’t be more incorrect. Cement refers to a broad variety of fine-ground powders that harden when mixed with water.  

On the other hand, concrete is a hardened construction material made by combining a chemically inert mineral aggregate – usually sand, crushed stone or gravel, or a mixture of two or all three, cement as the binder, chemical additives (optional) and water.

Cement is therefore is only one of the many components of modern concrete.

The cement and water that make up the paste coats the surface of the aggregate, both the fine and the coarse ones. Through hydration, a chemical reaction, the paste hardens as it dries to form the rock-like mass which is concrete.

concrete tube

When concrete is dry, it naturally acquires a hardness and consistency that can be likened to stone. This makes it deal for road construction, building of bridges, factories, railroads, sewerage and water supply systems, airports, mass transportation systems, waterways and other durable structures.

Concrete may differ in strength and density, depending on the proportions of its three key ingredients: cement, water and aggregate.

 

Quality Depends on Proportion

Depending on the kind of structure that would be made with the concrete, you will prepare proportions of water, cement and aggregate. These proportions and how you mix these elements will determine the quality of the concrete and the final structure.

pouring cement in floor

Thus, if the mixture does not have enough paste to fill the gaps between the aggregates properly, it becomes difficult to manipulate the concrete and your mixture may become porous and rough on the surface.  

On the other hand, if the mixture contains excess cement paste, it will be easy to apply, and the final concrete will be smooth on the surface but can easily crack.

Given this, we see that the strength of the concrete depends on the ratio of water to cement.

This ratio refers to the weight of the water used to mix the concrete divided by the weight of the cement used.

To produce high-quality concrete, lower the ratio of water to cement as much as possible. Ensure that the fresh concrete can be properly placed and consolidated.

Setting the proportion of concrete can be done in two ways:

 

By Volume

This is usually used for small jobs. In doing this, you use gauge boxes to measure the fine and coarse aggregate.

adding cement in mixer

Each gauge box has a volume equal to one bag of cement. This method is less accurate but takes less time.

 

By Weight

This method is way more accurate and makes for a more uniform process. It doesn’t have the uncertainties of bulking, hence is generally preferred over volume batching.  

mixing cement

In either case, the proportions of cement, water, and aggregate should produce concrete that has the following properties:

  • Maximum density – the concrete should be as strongest and water-tight as it can be.
  • Can be easily manipulated while it’s fresh. it should be easy to economically place in the formwork.

With these,  you are ready to make your first concrete. But, how do you go about it?

 

Step 1: Gather or Buy the Raw Materials

You may have to buy cement, but can gather the two other raw materials: water and builder’s sand/gravel or crushed limestone.

Determine the volume of concrete that you’ll need. You can do this by multiplying the thickness of the target area to its square footage.

 

Step 2: Find a Suitable Container for Mixing  

You may not always have a mixer unless you are in the construction business. But you can always borrow or rent a mechanical mixer. Don’t worry too much on the cost as this will considerably reduce the labour required.

adding cement in mixer

For a small project, improvise a manual mixing box by building one from wood planks.  You can also use a strong wheelbarrow to mix the materials.

 

Step 3: Mix The Cement and Sand

Start off by preparing your dry mix. You do this by mixing the cement and sand. You can choose from these  two concrete preparation methods:

  • Method 1 –  make a basic mixture for mortar using the ratio of 1 to 2 to 3 for water to cement to sand by volume.
  • Method 2 – create a general purpose concrete using the ratio of 1 to 2 to 3 for cement to sand to gravel by volume.

 

Step 4: Add the Crushed Stone or Gravel  

Add the gravel or crushed stone at a ratio of up to 5 portions of gravel for every 1 portion of cement and sand mixture.

adding cement in mixer

Don’t worry. The high ratio of gravel has no adverse effect on the tensile strength of the concrete unless it’s too much. Just be sure to leave enough cement paste to fill the spaces between the gravel. If this doesn’t happen then you know you’ve added too much of the gravel.

Note that concrete with too much gravel will be difficult to level and it will be hard to achieve a smooth finished surface where it’s curved.

 

Step 5: Add Water 

Water determines the quality of your concrete so it’s best to add water to the mixture slowly. Mix out the concrete continuously every time you add water until the concrete becomes plastic enough to place in your form.

 

Step 6: Mix the concrete thoroughly  

Once the desired volume of water has been added, continue mixing until the concrete achieves a uniform consistency.

Pouring out the cement from mixer

The final wet concrete should be even all over, and have no packets of dry material. About two or three extra minutes of mixing after the desired consistency has been achieved will give you the perfect concrete.

With your concrete ready, you can then pour it and float it to create the structure you intended.

Diamond Grinding: When is the Proper Time to Do It?

Diamond grinding is the removal of concrete using diamond saw blades that are mounted on a rotating drum. The technology helps remove scallops or bumps that cause poor quality of ride on the surface by improving its texture and overall friction.

It is one of the ways to profile concrete. It has gained recognition as a leading method for resurfacing and maintaining roads in various regions around the world.

person doing diamond grinding

Diamond grinding can correct a broad range of concrete and asphalt surface imperfections, restoring its function and appearance. It can correct irregularities such as roughness and faulting on concrete roads and pavements.

Roughness can come from construction problems, producing a uniform appearance and skid resistance. These are areas where diamond grinding is done. Plus, it can restore asphalt and concrete pavements, depending on the exact traffic requirements.

person preparing a concrete floor 1

Depending on the type of abrasive used, grinding can also improve the appearance of a surface, up to the point that it is comparable to high-quality polished floors in modern showrooms and leading art galleries. Note that you can do diamond grinding on both new and old concrete floors.

Most of the irregularities corrected through diamond grinding are often caused by:

Slab warping – this often comes from the moisture gradient between the opposite surfaces of the slab.  

Construction curling –  this usually happens within the first month after construction. This is because the excess water evaporates, causing the concrete to shrink.

Faulting – most commonly caused by slab pumping, and;

Roughness – caused by the actual construction work.

Both commercial and residential properties can benefit from diamond grinding. With diamond grinding, riders can count on road surfaces that are consistent and level. This is synonymous to smoother, safer rides and more comfortable journeys overall.

But be aware that the resulting pavement depends on the spacing of the diamond blades. This spacing is normally determined by the hardness of the aggregate.

 

Types of projects that require diamond grinding

Diamond grinding is often done alongside several other concrete pavement preservation techniques such as full- and partial-depth repair, road slab stabilization, resealing of joints and cracks, and cross stitching of longitudinal cracks.

For roads, the idea is to produce a leveled but far less slippery surface.

On the other hand, grinding jobs inside residential spaces and commercial buildings aim to achieve a smooth and almost marble-like sheen. The surface should be completely free of striations following a diamond grinding work.

Each project has a corresponding diamond blade and blade alignment on the grinder. Among the projects that require diamond grinding include:

 

Overlay installation

Diamond grinding is often necessary when installing decorative concrete overlays in a building’s interior. Such an overlay or micro topping restores and enhance the appearance of a worn, discolored or damaged the concrete floor.

In most cases, you need to grind a thin layer on the surface before you can put the overlay particularly if it’s cement-based.

person preparing a concrete floor

Regardless of the type of overlay, surface preparation is important. In this, you clean the substrate, remove any existing coatings before profiling or roughening the surface for good bonding.

Diamond grinding is just one of the several methods to profile concrete surfaces. Others are shot blasting, acid etching, sandblasting and scarifying.

 

Floor levelling

For both residential and commercial buildings, uneven floors caused by problems overlooked during construction can be corrected by grinding off the high spots.

uneven floor

The floor can then be coated or polished for a great finish.

 

Concrete pavement and floor repair

Rain damaged concrete and coatings on both pavements and floors can be repaired by diamond grinding. A suitable blade will grind the damaged concrete surface, have it sealed off to restore a superior look.

 

Road and pavement construction

Depending on the degree of skid resistance needed, well-spaced diamond blades on a rotating drum can remove any surface irregularities and make a safer road.

Despite numerous projects where diamond grinding is needed,  it should only be done only when necessary.  

1. It reduces pavement thickness

Since grinding involves removing a thin layer of the pavement, it can lessen the longevity of the pavement’s use.

2. Grinding does not make up for structural or material deficiencies

Diamond grinding does not fill structural or material deficiencies such as cracks and weak or thin layers. Neither does it correct any material problems such as reactive aggregates.

Additionally, in cases where load transfer is deficient, any faults in the pavement joints corrected by grinding are likely to re-occur.

So, before starting any diamond grinding work, it’s best to get expert advice from a concrete cutting and drilling company or a seasoned concrete grinding professional.

 

You Might Also Like To Read

Handy Tips for Diamond Grinding Services and Keeping Tools in Top Condition

Four Key Steps in Concrete Grinding and Polishing

Diamond Grinding Concrete Floors, Tools, Methods, and Basic Tips

 

A New Invention: Solar Powered, Glow in the Dark Cement

 

When scientist José Carlos Rubio came up with glowing cement – cement that glows at night, no doubt he intended it to illuminate roads and highways at night.

Ever wondered what it would feel like to ride at nght on a road that does not have the characteristic marginal broken white lines? These will make driving at night quite a breeze.

They provide the needed assist on narrow roads and in remote parts of town where roads are dimly lit or are outright dark.

Imagine not having to rely on traffic lights or your own vehicle’s headlights to see the road.

bioluminscent natural lightning
© cnn.com

Photoactive materials to normal cement  

Mexican scientist Rubio Avalos altered the fine structure of cement over a period of nine years and came up with the variety that could glow in the dark. This breakthrough involved adding photoactive materials to the normal cement. This made it absorb and emit light.

It came with the pressing challenge of finding a way to turn the characteristically opaque material, cement, into something that could soak up UV rays and light up.

At the end, he was able to alter the microstructure of cement – starting by mixing the cement powder with water to make a gel-like material. The gel formed makes the material form crystals.

The crystals are then removed to form Rubio Avalos’ glowing concrete. The resulting material allows sunlight to penetrate and be retained within the cement matrix without being reflected.

hands glowing in cement
(C) cnn.com

With its glow-in-the-dark properties being able to last for a minimum of 100 years, and the technology being able to work even on cloudy days, the cement brings about unlimited possibilities.

 

Works indoors too

For starters, the solar powered, glow-in-the-dark cement can work indoors. The cement will draw the glow properties from the little UV rays in the course of the day to use during the night.

glow in the dark cement indoor design
© The Polished Concrete Company

The cement emits either green or blue colours. The light intensity could also be adjusted based on the place where the material is to be used or applied.

Avalos explained that the cement can be charged even indoors or during cloudy days because it’s charging mechanism does not depend on direct sunlight. Plus, the material can emit light continuously for 12 hours before it requires a recharge.

The materials being from dust, clay or sand, with the residue being water steam makes the glowing cement ecologically friendly. These properties make the cement is suitable for both interior and exterior applications.

Given these features, Avalos said that some organizations have already made plans on how to make use of the product.

Médecins Sans Frontières, a non-government organization intends to illuminate bathrooms where there are electricity and lighting problems. With this, they want stop the idea is to reduce the danger that women are potentially exposed to when they enter dark public toilets.

 

Projects that can use this type of cement

There are unlimited uses for glowing cement in the construction industry, among these are:

 

Road construction

A solar-powered cement that glows in the dark and can withstand the harsh effects of the sun’s UV rays for at least 100 years revolutionizes roads.

For one, instead of using floodlights, it is more cost-effective to use solar-powered cement in areas that require minimal street lighting.

glowing cement use in road
© cnn.com

Referred to as solar road, this has already been tested in the Netherlands with stones that charge during the day and glow at night to illuminate a pathway for bikes.

Before, the materials used to illuminate the bike path are made of plastic that easily degrades after a couple of years of exposure to the sun.

In contrast, solar powered cement is durable and can be a relatively permanent solution to road lighting.

 

Decor for Interiors

Rubio’s work is not limited to cement. Since it is applicable for It can also be used in plaster.

glowing pathway
(c) InHabitat

This is especially breathtaking, especially against dark backgrounds. This makes it possible to create luminous wall coatings.

Imagine houses with walls that emit light at night. This can be good for both security and decoration purposes.

Constructing swimming pools that can be safely used at night

Rubio Avalos says governments, businesses, and NGOs have requested that his cement to use to illuminate the inside of swimming pools.

glowing swimming pool
© Rolling Stone Landscapes

With this, you won’t need for alternative lighting and makes night swimming safer.

 

Decorating cities in red, blue and purple

Though the glowing cement is available only in bright green and marine blue colors, Avalos is working to produce varieties that can glow in red, white and purple. When these are realized, we can only expect buildings adorned with the said colors.

Although the solar powered glow-in-the-dark cement is currently battling with issues of cost of production, there’s solid hope that all these expectations will be actualized in the near future.