Cutting concrete can be done in various ways, one of the simplest way is cutting off concrete with concrete saws and saw blades. It produces a perfect cut and you can cut in shapes you want easily. The only disadvantage for concrete saw and saw blades is it’s too dusty, so you have to prepare face dust masks or glass spectacle so that it can protects your eye and mouth from the dust.
Sometimes concrete curb has to be cut, but in this article that will be only cutting off concrete slab. Some precast concrete curb is constructed in lengthy way, after the precast concrete curb is properly cast, concrete cutting machine has to be used to cut them in certain length and ready for delivery.
How To Cut Off Concrete With Concrete Saws and Saw Blades
1) First, you may need to have a concrete saws and saw blades. You have to learn how to use it.
2) Find a concrete slab that is meant to be cut.
3) Use a plywood as the guideline.
4) Turn on the engine of concrete saws and saw blades.
5) Wearing face dust masks or glass spectacle to protect your eyes from the dust.
6) Draw a line by cutting the concrete slab in shallow and use the plywood as guideline.
7) Following the shallow line, cut the concrete slab in the depth you want.
8 ) After done one side and you can cut another side.
9) Do some cleanup work.
10) Done!
It’s the easiest way to cut off the concrete with concrete saws and saw blades, but it’s good to have safety equipments to protect workers when cutting the concrete with the machine. In construction, contractor always says “Safety First” before the work can be done!
Concrete paving block is a type of floor and commonly used on roadside, walkway and etc. There is few types of paving block such as interlocking paver, landscape paver and etc. All of them have its’ own features and installation procedure.
Normally people uses concrete paving block to decorate their house’s external floor because concrete paving block has many colours and unique pattern. Paving block manufacturer mixes it with a few different of colour to make the pavers the look of natural stone, like granite or slate. Contractors use it on walkway as well.
How To Install Concrete Paving Block
1) Basecourse
Taking the existing sub-grade or soil conditions and the anticipated traffic loading into consideration, an adequate thickness of well compacted base course must be provided to ensure good pavement performance. Existing bitumen or concrete surfaces need not be removed and can act as good sub-grade.
2) Edge Restraint
Adequate edge restraints should be provided at this stage along the perimeter of paving area to prevent lateral movement of blocks. They may be in the form of concrete curbs or vertical edges of exiting structures.
3) Sand Bedding Layer
A layer of sand should be spread loose and screeded to a uniform thickness such that its compacted thickness would be approximately 30mm. It is important that the sand layer remains undisturbed prior to the laying of blocks.
4) Laying The Concrete Paving Blocks
Concrete paving blocks are placed side by side on the sand bed with gaps of approximately 2mm between adjoining blocks.
5) Cutting The Concrete Paving Blocks
Paving blocks an be cut to fit edges and awkward corners.
6) First Pavement Compaction
Block pavement is compacted with a hand-guided plate vibrator until it is firmly embedded in the sand layer.
7) Sand Filling
After first compaction, fine sand is brushed in to fill gaps in between paving blocks.
Second Pavement Compaction
Hand-guided plate vibrator is applied once again to ensure that sand filling in the gaps are fully compacted to stablize the block pavement. Steps 7 and 8 may need to be repeated until gaps are completely filled with fine sand. Once the remaining surface sand is removed, the block pavement is ready for use.
Usually concrete curb is built by using hand or can be done by using precast concrete curb which is using hand as well, but there is another method to lay concrete curb which is using concrete agitator. The procedure is not as difficult as you think, it’s just a simple work to lay the concrete curb by using concrete agitator.
Contractor uses concrete agitator to mix the concrete which require larger mixture or large quantity of concrete, so contractor might need to mix the concrete by using agitator. Usually worker just has to throw all the concrete mixture material such as sand, water and cement into concrete agitator and the roll will be starting to swing and mix the concrete until it’s properly mixed.
How To Lay Concrete Curb With Concrete Agitator
1) Throw all the concrete mixture material such as cement, water and sand into concrete agitator, swing the roll until the concrete is properly mixed.
2)Concrete curbing machine has to be used, set the concrete curbing machine at the place where the contractor want to build the concrete curb.
3) Make sure the opening of concrete agitator is aiming to the concrete curbing machine so that the concrete can be dropped into the concrete curbing machine.
4) Everything set on place, concrete agitator opens its’ opening and the concrete is flow out into the concrete curbing machine, a worker is controlling the concrete curbing machine, another worker is pulling out the concrete from the opening of concrete agitator to make it flowing out faster into the concrete curbing machine.
5) The worker who controls the concrete curbing machine is pulling the concrete machine so that the concrete curb can be lay on shape. After that, the concrete curb is done in shape in short time.
The advantage of using concrete agitator to build concrete curb is the minimum usage of labour which can be saving the labour cost. Besides this, this method is easy and fast, it can saves up a lot of time and cut off the expenses. From the video clip, it only requires 3 workers to lay the concrete curb. Due to current economic downturn, contractor must plan and decides the cheapest and most economic way or method to construct their structures.
Precast Concrete Drop Kerb is one type of concrete curb that used on the roadside. Other than constructed on the roadside, it’s used on the pedestrian crossing too. The precast concrete drop kerb is constructed as a slightly slanting slope. When walkway passengers are walking on the walkway, they cross the road and this precast concrete drop kerb makes them easy to cross the road.
How To Construct Precast Concrete Drop Kerb
That’s not difficult to construct these kerb, since the drop kerb is a precast product and it saves a lot of time instead of casting it on the site. Most of the contractors use precast product instead of casting it on the site, because it’s not only saving cost and also times.
1) Earthwork
You have to make sure that the condition of soil is strong enough to support the works on the ground. Otherwise, you can do a soil investigation to test the condition of soil. After that, fill about 200mm thick sub-base.
2) Concrete Base
After the earthwork is done, construct a concrete base to support the drop kerb. Mass concrete can be used to construct the concrete base since the load of the drop kerb is small. The concrete base is a cast-in-situ concrete. The insitu concrete surfaces below ground level shall be coated with road oil to avoid the water flow into the concrete.
3) Drop Kerb
Lay the drop kerb on the concrete base. The drop kerb base have to haunch with Bituminous Double Coat Paint before lay on the concrete base.
4) Pavement & Road Work
After the drop kerb is done, other works like pavement works and road works to be constructed. Pavement works consist of lower roadbase, upper roadbase and wearing course. While road works consist of 200 x 100 x 60mm grey paving blocks in Herringbone Pattern.
When I was preparing a Bahrain Tender, I saw a lot of different type of concrete curb in the drawings. They had different shape in different situation, and the concrete curb had different name in different situation such as Standard Kerb (Pedestrian Crossing), Standard Upstand Kerb and Standard Kerb Laid Flat. It’s all precast product and it can be constructed in a short time and low cost. I will be explaining all of them in this article.
Type Of Standard Kerb
1) Standard Kerb (Pedestrian Crossing)
Pedestrian crossing kerb will be used when there is a drop occurred on the roadside for Pedestrian Crossing or we called it Zebra Crossing. The depth between the kerb and finished road level is about 25mm thick only, the kerb will be slowly slim down and end up the depth is same with the finished road level. The 250×125 half battered kerb will be used in this situation. It’s a type of dropped curb that used on the pedestrian crossing.
2) Standard Upstand Kerb Standard Upstand Kerb is a normal type of concrete curb that used on roadside. When there is a Pedestrian Crossing, Standard Upstand Kerb will be joined with the Standard Kerb (Pedestrian Crossing) as what I mentioned above. 250 x 125 Half Battered Kerb will be used. The depth between concrete curb and finished road level is about 150mm thick.
3) Standard Kerb Laid Flat Standard Kerb Laid Flat is a very wide but thin concrete curb. The depth between concrete curb and finished road level is about 25mm thick only. Same as Standard Kerb (Pedestrian Crossing) and Standard Upstand Kerb, 250 x 125 Half Battered Kerb is used too.
Second Pavement Compaction
