(4) Conversion of material proportions.
The principle of conversion is similar to the conversion of concrete strength grade, the amount does not change, only the material change part, and the conversion formula is conversion ** = original quota ** + quota concrete amount (unit price of concrete - unit price of concrete exchanged) + other material changes.
Example 4-6] The current design requires that the roof cushion is 1:1:10 cement lime slag, and the budget of 10m3 of the sub-project is calculated** and the consumption of materials per fixed unit.
Solution] 1) Determine the conversion quota number 1H0018 (quota omitted).
The ratio of 1H0018 cement lime slag is 1:1:8, and the dosage is 1010m3 10m3, the budget base price is 137587 yuan 10m3.
2) Determine the base price of concrete for replacement and replacement (appendix omitted).
Check the Appendix: The ratio of 6b0462 is 1:1:8, 5828 yuan m3, exchange 6b0463 ratio is 1:1:10, 5126 yuan m3
3) Calculate the converted budget base price.
1H0018 exchange = original quota ** + quota concrete consumption (unit price of concrete exchanged - unit price of concrete exchanged).
1375.87+10.10×（51.26-58.28）=1304.97 (Yuan 10m3).
4) Analysis of material consumption after conversion.
Labor cost: 238$14.
Machinery fee: 000 yuan.
Cement 32Level 5: 14600×10.10=1474.60（kg）。
Quicklime: 7300×10.10=737.30（kg）。
Slag: 0984×10.10=9.94（t）。
Water: 503m3。
5) Conversion of cross-sections.
The cross-sections of the components in the budget quota are determined by means of a comprehensive weighted average calculation based on different design criteria. If the design cross-section is inconsistent with the quota cross-section, it should be converted according to the relevant provisions of the budget quota.
The formula for the consumption of the converted material is:
Converted material consumption = design cross-section (thickness) quota consumption.
For example, the cross-section or thickness of the timber indicated in the base price item is a gross cross-section, and if the cross-section or thickness indicated in the design drawings is a net material, the planing loss should be increased. The planing of board and fang timber increases by 3mm on one side, increases by 5mm on both sides, and the volume of logs per cubic meter increases by 005m3。
6) Conversion of mortar.
The masonry mortar conversion is similar to the conversion of concrete components, and the conversion formula is:
Conversion** = original quota** + fixed mortar amount (unit price of mortar in exchange - unit price of mortar in exchange).
Example 4-7] The design of an empty flower wall in a project requires standard bricks 240mm 115mm 53mm and m25. Mix mortar masonry, try to calculate the budget of the sub-project and the consumption of materials in the fixed unit.
Solution] 1) Determine the conversion quota number 1D0030 (quota omitted). 1d0030，m5.0 mixed mortar masonry, the dosage is 118m3 10m3, the budget base price is 108730 yuan 10m3.
2) Determine the base price of concrete for replacement and replacement (appendix omitted).
Check Appendix: Swap out 6b350 m50 mixed mortar masonry 8078 yuan m3;Swap in 6b349 m25. Mixed mortar masonry 7326 yuan m3
3) Calculate the converted budget base price.
1H0018 exchange = original quota ** + quota mortar amount (exchange mortar unit price - exchange mortar unit price).
1087.30+1.18×（73.26-80.78）=1078.43 (Yuan 10m3).
4) Analysis of material consumption after conversion.
Labor cost: 33768 yuan.
Machinery fee: 886 yuan.
Standard brick 240mm 115mm 53mm, 402 thousand pieces.
Cement 32Level 5: 18200×1.18=214.76（kg）。
Extra-fine sand: 115×1.18=1.36（t）。
Lime plaster: 0165×1.18=0.19（m3）。
Water: 140m3。
vii) Conversion of coefficients.
According to the coefficient specified in the quota description, multiply the base price of the corresponding quota (or a part of the quota work and material) to obtain a new unit price.
Example 4-8] A project flat foundation earthwork, the construction organization design is specified as mechanical excavation, there is 121m3 of wet soil in the dead corner of the mechanical construction, manual excavation is required, and the direct cost of completing the sub-project is calculated on a trial basis.
Solution] According to the description of the earthwork division, it is known that when manually digging wet soil, the corresponding quota item is multiplied by the coefficient of 118 calculated, the earthwork that can not be constructed by machinery is multiplied by the coefficient of 1 according to the corresponding manual excavation earthwork quota5。
1) Determine the conversion quota number and base price. The quota number is 1A0001, and the base price of the quota is 69960 yuan 100m3.
2) Calculate the conversion base price.
1a0001 for = 6996×1.18×1.5=1238.29 (Yuan 100m3).
3) Calculate the direct cost of completing the sub-project.
1238.29×1.21=1498.33 (yuan).
8) Other conversions.
The quota conversion that cannot be included in the above conversion types is only an example of the conversion process due to the large and miscellaneous content of such quota conversion.
Example 4-9] The design requires the construction of 1:2 cement mortar and 8 waterproof powder (one layer method) for the moisture-proof layer of the wall foundation of a project, and the budget of the sub-project is calculated.
Solution] 1) Determine the conversion quota number 110058, and the quota base price is 58576 yuan 100m3.
2) Calculate the amount of waterproof powder that is exchanged in and out: the amount of waterproof powder is 5500kg/100m2；The amount of exchange is 12954×8％=103.63（kg/100m3）。
3) Calculate the conversion base price (the unit price of waterproof powder is 1.)17 yuan kg).
110058 exchange = 58576+1.17×（103.63-55.00）=642.66 (Yuan 100m2).
Although there is no fixed formula for other conversions, the idea of conversion is still to subtract the cost of the swap-out part from the original quota** and add the cost of the trade-in part.
Material spread adjustments.
Material price difference adjustment refers to the adjustment of the material price difference in the adjustable material ** contract, during the construction period, due to non-construction unit reasons, the material ** growth exceeds the allowable range, and the material price difference can be adjusted at the time of settlement. In the settlement of construction projects, the adjustment of material price difference plays a very important role in the settlement of construction projects, and accurate adjustment of material price difference can improve the work efficiency of project settlement and reduce disputes. Common material price difference adjustment methods include real adjustment, comprehensive coefficient adjustment, real adjustment and comprehensive coefficient combination and index adjustment.
1) According to the actual adjustment method.
This method is to adjust the difference directly according to the actual occurrence of the material **, and its calculation formula is:
Adjustment factor of a certain material = comprehensive adjustment factor k1 (price difference of various materials) k2
where k1 is the proportion of various materials in the engineering materials;
K2 - the proportion of various engineering materials in direct costs.
The adjustment amount of the price difference of the unit project material = the comprehensive price difference coefficient and the direct cost of the budget fixed amount.
The advantage of the comprehensive coefficient adjustment method is that it is easy to operate, fast and easy to implement
The disadvantage is that it relies too much on the measurement of the comprehensive coefficient by the cost management department.
In practice, the relationship between the representativeness of the project selection, the authenticity and accuracy of the material variety and the short-term fluctuation often leads to the error of the project cost calculation.
3) Combination of actual adjustment and comprehensive coefficient.
According to statistics, the value of three materials accounts for about 68 in the material cost, and a large number of local materials and other materials only account for 32 of the material cost. In fact, it is not necessary to comprehensively sample the widely distributed materials in the subheadings. Therefore, in some areas, the three materials or the main materials are adjusted by sampling, and other materials are adjusted with auxiliary material coefficients, so as to effectively improve the accuracy of the project cost and reduce a lot of tedious work.
4) ** Index Adjustment Method.
It is a method of adjusting the price difference of engineering materials one by one according to the current building materials ** or price difference index announced by the local cost management department. This method belongs to the amount of compensation for the difference, the calculation is large and complex, and often requires the cost management department to pay more manpower and time.
The specific method is to first calculate the budget and market of various local building materials, and then comprehensively sort out and regularly publish the ** index and price difference index of various building materials.
It is calculated as follows:
** index of a certain material = the current budget price of the material The price taken in the quota of the material.
The spread index of a certain material = the ** index of that material - 1
* The advantage of the index adjustment method is that it can reflect the changes in building materials in a timely manner, with good accuracy and adapt to the dynamic management of construction projects.