Measurement of Concrete Works in Chilean Construction
Measurement of Concrete Works
General
1 Measurement by Volume
Concrete works are measured by volume, excluding the space occupied by steel trusses and pipes embedded within them, with a diameter or transverse dimension not exceeding 0.25 m.
2 Measurement of Plain and Reinforced Concrete Elements
Regardless of the dimensions and shapes of plain or reinforced concrete elements, measurement is done by volume, except for glazed rib tiles that form ceilings and foundation slabs (Radierer).
3 Deductions for Openings
In measurements of plain or reinforced concrete, all openings, hatches, or openings with a top surface area greater than 0.05 m2 are deducted.
4 Separate Measurement by Concrete Type
Concrete measurements should be made separately for each type of concrete, concrete element, and/or type of molding used, even if they constitute the same element or group.
Reinforcing Bars for Concrete
1 Measurement Based on Mass
Reinforcing bars are measured according to their mass (kg) derived from detailed drawings. This is done by multiplying the nominal mass of each nominal diameter by the length of each bar, considering the recent armor measurement, the distribution of supplies, and the stirrups of beams and pillars.
2 Measurement of Iron Sold in Rolls or Bars
For iron sold in rolls, the length is measured for each nominal diameter. For iron sold in bars, the commercial length should be considered, indicating the total number of bars for each nominal diameter and commercial length. Additionally, the mass of the bars for each nominal diameter and the total mass should be shown separately.
3 Separate Measurement for Long Rods
Long rods exceeding 12m should be measured separately.
4 Additional Elements and Percentage Increase
A 5% increase should be added to the measured nominal weight of the reinforcement to account for the following additional elements:
- 4% for all barriers between mesh armor tiles, upside, guides, position items, and trimmings.
- 1% for larger diameter and/or length of the bars for nominal consideration in the measurement.
5 Measurement Based on Number of Constraints and Legs
If the project specifies the number of constraints and legs per m2 of element (walls, beams, or slabs), these should be included in the measurements. In this case, the percentage of loss shown in 6.2.4 is not considered.
6 Inclusion of Mooring Wire
Mooring wire reinforcement is included in the price of the reinforcing bars.
7 Splicing of Vertical Reinforcement
Vertical reinforcement in pillars and walls is considered, unless otherwise stated in the project specifications, to be spliced into the next floor over a length of 40 times the diameter of the thicker spliced armor.
8 Penetration of Vertical Reinforcement in Foundations
The penetration of vertical reinforcement in foundations, if not specified in the plans, is estimated at 40 times its diameter, with a minimum of 10.1 m from the bottom of the excavation.
9 Stirrups in Pillars
Stirrups in pillars are considered to be spread over the entire length of the longitudinal reinforcement, disconnecting the beam crossings.
10 Percentage of Loss for Subcontracted Work
If the reinforcement work is subcontracted in the mode of selling or lump sum (per kg of iron installed), which includes provision, preparation, transportation, and/or placement of the reinforcement bars, a percentage of loss is considered for the measurements of large commercial planes, regardless of the 4% established in 6.2.4, if applicable.
Airspace in Formwork, Foundations, and Foundation Slabs
1 Measurement of Formwork
Formwork is measured by its surface area or volume, indicating its thickness.
2 Measurement of Foundations
Foundations are measured by their actual volume, between their lower limit in the field or the formwork, and the upper boundary that separates them from the elements they support. Elements with different nature, cement dosage, width, or unit price are included in a separate item.
3 Measurement of Beams, Slabs, Chains, Ropes, Pillars, and Benches
Beams, slabs, chains, ropes, pillars, benches, and other elements that are part of or join the foundation elements are measured according to the requirements of the relevant clauses based on their nature and nomenclature.
4 Measurement of Pile Foundations
Pile foundations are considered in one or more items, including clothing, transportation of components, labor, and mechanical driving, according to the circumstances of each particular case. The length of the piles should be noted.
5 Measurement of Flat Radius
Flat radius is measured by its surface area, indicating its thickness.
Measurement of Concrete Walls (Plain or Reinforced)
1 Calculation of Wall Volume
To calculate the volume of walls without the interposition of beams or slabs, the height between the upper levels of the slabs is considered.
2 Measurement of Wall Height with Beams
If there is a beam parallel to the wall with a width greater than that of the wall, the height is measured to the lowest level of the beam.
3 Measurement of Wall Height with Different Slab Levels
If the slabs have different levels on each side of the wall, the upper level facing the highest slab is considered.
4 Lower Limit of Walls
The lower limit of the walls should generally be the point where the thickness or cement dosage changes, requiring a separate item for the lower support element, such as another wall, a beam, a foundation, or any foundation in general.
5 Length of Walls for Airspace Calculation
For airspace calculation, the length of the walls is measured between walls, pillars of different thickness, and/or those with different cement dosages.
6 Measurement of Intersecting Walls
In the case of crossing or intersecting walls with the same cement dosage, the length is measured so that the common area between them is considered only once.
Measurement of Concrete Pillars and Unassembled Elements
1 Measurement of Pillar Height
The height of the pillars is measured in the same way as the walls.
2 Consideration of Different Slab Levels
Where slabs have different levels, the measurement is considered as described in 6.5.3 to 5.4.3.
3 Lower Limit of Pillars
The lower limit of the pillars is considered as indicated in 5.4.4.
Measurement of Beams
1 Length of Beams
For airspace calculation, the length of the beams is considered to be the span between supporting walls, pillars, or other beams.
2 Height of Beams
The height of the beams is measured between its upper and lower cladding. If there are slabs, the height of the beam is measured between the lower cladding and the upper level of the slab. If the slabs have different levels on either side of the beam, the top level of the highest slab is considered.
Measurement of Concrete Slabs
1 Volume Between Supporting Walls
The volume between supporting walls (free surface) is considered.
2 Inclusion of Acartelamientos
Acartelamientos are included in the volume of the slabs.
3 Measurement of Glazed Tiles
Glazed tiles are measured by their total area.
4 Measurement of Ribbed Slabs
Ribbed slabs constructed with prefabricated molding are measured by their total area.
5 Inclusion of Wall Thickness for Non-Concrete Walls
If the slab rests on a non-concrete wall without the interposition of a string or beam, the thickness of the wall must be included in its airspace.
Measurement of Stairs, Fireplaces, Ceilings, Cornices, Awnings, and Day Care Centers
These elements are measured by volume, in accordance with the provisions of the preceding sub-clauses for each of their constituent parts, with separate headings formulated covering the whole.
Measurement of Vaults, Domes, and Arches
For measurement purposes, vaults and domes are treated as slabs, and arches are treated as beams, considering their development in both cases.
Rule for Measurement of Various Elements
1 General Form
Elements are generally measured as slabs, pillars, walls, or beams, based on their form.
2 Intersection Areas
Intersection areas where several elements meet are conceptualized in the following order of precedence:
- Pillars and walls
- Beams
- Members