How to make a ramp with your own hands? What is the peculiarity of concreting a monolithic ramp and how to correctly calculate the material for a ramp with a slope? The article will tell you how to determine the parameters of the structure, calculate the length of the plane and the volume of material for a concrete ramp.
Ramp – a slope for strollers, bicycles, carts and other light wheeled vehicles. Most of these elements duplicate flights of stairs at the entrance to the building and are intended for the passage of wheelchairs and baby carriages..
Consumer requirements for the ramp:
- Slight incline, gentle enough to be climbed in a non-powered wheelchair.
- Smooth plane, no interference with movement.
- Resistance to weathering.
Structurally, the ramp is the body of a concrete flight of stairs (hereinafter – “the body of the stairs”) without steps. Another difference is the significantly lower bias. According to the requirements of SNiP 35-01-2001 “Accessibility of buildings and structures for people with limited mobility” and SP 35-101-2001 “Design of buildings and structures taking into account accessibility for people with limited mobility”, the slope of the ramp should not exceed 10%. A lifting plane of more than 9% is considered abnormal, i.e. a person with disabilities will need an assistant to climb it.
To simplify calculations and work, we will take the principle of creating a concrete staircase as a basis. By the location of the support, the ramp can be of three types:
- Fully supported on the ground or backfill.
- Supported by load-bearing walls (walls).
- Without support (monolith).
In all cases, the design of the ramp (like the stairs) will be different. In private construction, suspended marches and stairs are practically not found due to the complexity of the construction. We will consider a variant of the lifting plane on the “pillow”.
Determining the design parameters
Depending on the height of the end point, the ramp can be single-march or multi-march. The maximum length of the lifting plane is 9 meters, the lifting height of one march is no more than 80 cm (SNiP). In all cases, you should first of all provide for the sites before the arrival, after the ascent and intermediate (if there are several marches). After climbing, there should be no obstacles or barriers (doors, portals).
In the course of calculations, we will need to determine two main indicators:
- The shape of the ramp. If the lifting height is greater than the standard (or convenient), it should be divided into marches with an intermediate platform. The thickness of the concrete slab will remain unchanged..
- The total length of the ramp, taking into account the sites.
Suppose we need a ramp 1 meter wide and 1.2 meters high. Sufficient plate thickness is 100 mm. Support walls – reinforced brickwork 125 mm (half brick) or cinder block 200 mm.
Calculating the ramp
With a slope of 8%, the normal ratio of height to length is 1:12, that is, for 1 meter of vertical rise there will be 12 meters of the ramp. With a height of 1.2 m, the length of the ramp in the plan will be equal to:
- Lpandas = Hvert / 0.08 = 15 m
It is not always convenient to build a 15-meter continuous ramp and this contradicts the requirements of SNiP. Therefore, it should be split into two equal marches of 7.5 m each (in plan). Height of intermediate platform level:
- Harea = Hvert / 2 = 1.2 / 2 = 0.6 m
The length of the lifting plane of the ramp (according to the Pythagorean theorem) will be equal to:
- Lflat = square root. from (H2vert + L2pandas) = square root. from 1.44 + 225 = 15.04 m, we take 15 m
We accept the intermediate platform 2×1 m (2 m2).
Note.The design of the ramp can vary significantly depending on the location – along the wall, parallel to the corner or adjacent marches. The article discusses the option of adjacent marches.
Total length of concrete slab:
- Lslabs = Lflat + Larea = 15 + 2 = 17 m
With a width of 1 meter, the area will be 17 m2.
The volume of concrete for the ramp:
- Vbet = Lslabs x Hslabs = 17 x 0.1 = 1.7 m3
We calculate the volume of the walls. To do this, add up the wall areas and multiply by the thickness (it may vary). Since the shape of the walls is conventionally a right-angled triangle, we will use the formula:
- Swalls = Hvert x Lpandas = 1.2 x 15 = 18 m2
The volume of the walls with a thickness of half a brick:
- Vwalls = 18 x 0.125 = 2.25 m3
The number of bricks for the walls will be:
- Nkirp = Vwalls / V1kirp = 2.25 / 0.002 = 1125 pcs.
The volume of backfill material will be approximately equal to the area of one wall multiplied by the width (1 m):
- S1walls = Swalls / 2 = 18/2 = 9 m2
Backfill volume is 9 m3.
Reinforcement calculation. The slab on the pillow is reinforced in one layer with a knitted mesh frame made of reinforcement A3 O 14-16 mm with a cell of 150 mm. The main nuance of concreting the ramp is that reinforcement barriers are needed, which must also be taken into account. They are installed (with a slope of 8%) with a step of 2 meters, for each there are 2 pieces. 1 m each, total 15 m.
Number of longitudinal bars:
- Nprod = width / step = 1 / 0.15 = 6.67 = 6 pieces.
Longitudinal reinforcement length:
- LArmenian food = Lflat x Nprod = 18 x 6 = 108 lm. m
Number of cross bars:
- Npoper = Lflat / step = 18 / 0.15 = 120 pcs.
Shear reinforcement length:
- Lpoper = Npoper x width = 120 lin. m
Total reinforcement length:
- Larm = Lprod + Lpoper + Lbarrier = 108 + 120 + 15 = 243 lin. m
1. After the position of the plane relative to the ramp is finally determined, the site should be marked for the future structure. Use cords and pegs to do this. Try to maintain the internal width of the ramp first.
2. After the breakdown, it is necessary to arrange the foundation for the brick walls. Section of the beam under the wall in half-brick 200×200 mm.
3. Stretch the cords according to the slope of the lifting plane.
4. Then we lay out the supporting walls made of bricks according to the selected principle of the ramp device. If the ramp goes around a corner, only one wall is needed (the other is the building wall).
Attention! Reinforcement of the walls, especially the corners, is of great importance – they must withstand the load from backfill and ramming. Apply masonry mesh every 2 rows.
5. Masonry should be kept for 21 days.
6. Fill up the bosom between the walls with a rammer every 200–300 mm. Tamping should be done carefully, especially near walls.
7. We lay geotextiles or polyethylene (so that the concrete does not mix with the backfill)
8. We knit the reinforcement cage. The distance from the pillow to the net is 50 mm. The frame should go to the walls.
Attention! Remember to set up barriers.
9. We install the flanging on the dowels or press the panels from the outside. On the boards we put marks on the top of the plane.
10. The ramp is concreted from bottom to top..
The formwork can be removed the next day. After 28 days, you can install handrails or erect walls.
A concrete ramp can serve as a base for asphalt, paving slabs, or other types of finishes. Its exact dimensions are determined by the needs of a particular facility. But the basic principles of its construction, described in this article, remain unchanged..