Quality control indexes and requirements of soil solidified layer with 1. enzyme

Subgrade

(1) Before subgrade construction, restore the center line and retest the cross section, including on-site investigation, recording, penetration measurement of center line and level, laying center line piles and subgrade side piles, excavating side ditches, and equipping construction machinery (excavators, bulldozers, vibratory rollers, dump trucks, testing instruments, etc.) according to the volume of earth and stone and the requirements of the construction period.

(2) Layered filling, rolling, compactness, flatness and other indicators meet the design requirements; If the requirements are not met, base treatment (soft soil foundation treatment, pond embankment treatment, general foundation cleaning treatment, etc.).

(3) Embankment filling adopts information construction technology, and the construction is organized according to "three stages, four sections and eight processes. The construction shall be carried out in strict accordance with the process parameters determined in the test section, and the thickness of layers, the number of rolling times, the paving method, the filling rate and the water content of the soil material shall be controlled with emphasis to ensure the "three degrees", I .e. flatness, road camber and compaction.

(4) Select high-quality stone and reasonable mortar mix ratio, and arrange professional teams with rich experience in stone masonry and concrete construction to ensure the construction quality of slope protection works.

(5) The cross slope shall be constructed according to the design, which is beneficial to the compaction and drainage of the superstructure. The surface leveling error is within the control range, but no water is allowed. Reasonable arrangement of temporary drainage facilities and permanent drainage. The culvert pipe shall be arranged reasonably, the sand sinking shaft shall meet the requirements, the culvert pipe shall be pre-buried in elevation, which will not affect the compaction construction of the upper layer, and the sand wellhead shall be provided with temporary cover plate to prevent blockage.

(6) One-way cross slope shall be set at the curve. The elevation of the outer side of the road is higher than that of the inner side. The slope shall be reasonably arranged according to the actual situation.

(7) Subgrade deflection shall be less than 2mm. If filling is used for leveling, the soil quality of subgrade filling shall meet the requirements of specifications.

(8) To meet the following requirements, and then deliver the construction process.

Subgrade inspection items

Item Times	Inspection Items	Specified value or allowable deviation	Inspection method and frequency
1	Compaction (%)	≥ 96	Each operation section or more than 2000m, six times
2	Deflection (0.01mm)	≤ 200	Check 80~100 points of each two-lane assessment section (not exceeding lkm)
3	CBR(%)	Meet the specification requirements	Each operation section or more than 2000m, six times
4	Longitudinal elevation (mm)	10，-15	Gauge: every 200m,4 sections
8	Midline deviation (mm)	50	Theodolite: measure 4 points every 200m, and add HY and YH points to the curve.
6	Width	Not less than design	Meter ruler: 4 points per 200m
7	Flatness (mm)	20	3m ruler: measure 2 places × 10 feet every 200m
8	Cross slope (%)	±0.3	Gauge: every 200m,4 sections

General provisions for construction

(1) Construction quality requirements and inspection and acceptance mainly include material quality inspection, paving test sections, construction quality control and process acceptance.

(2) The rules and regulations for site test, quality inspection and handover acceptance between processes shall be established and improved during construction. The original records shall be complete, the data shall be accurate and the data shall be complete during the test, inspection and acceptance.

(3) The construction unit shall have or rely on a laboratory for various indoor tests on the materials used, and inspection equipment and instruments for site quality control.

(4) After each process is completed, inspection and acceptance shall be carried out, and the next process can only be carried out after it is qualified. If the test fails, rework shall be carried out until the requirements are met.

Material requirements

(1) Soil

Low liquid limit clay and silty clay are preferred for recommend. The maximum particle size of stone in soil should not exceed 60% of the design thickness of solidified layer, and the maximum particle size should not be greater than 53mm. The crushing value of the stone composition in the soil shall not be greater than 30%, and the organic matter content (weight ratio) shall not exceed 10%.

(2) Sand

Clean medium and coarse sand with silt content not more than 5% should be adopted.

(3) Gravel

The maximum nominal particle size of crushed stone should not be greater than 37.5mm, the maximum particle size should not be greater than 53mm, and the crushing value should not be greater than 30%.

(4) biological enzyme soil curing agent

Selection of 11X type TerraZyme enzyme.

(5) Cement

32.5# ordinary Portland cement shall be adopted, and the deteriorated cement shall be prohibited. The strength and stability of cement at each age shall meet the corresponding index requirements; the initial setting time of cement shall be more than 3 hours, and the final setting time shall not be less than 6 hours.

(6) water: clean human and livestock water can be used.

(7) The test items and methods for the raw materials of the bio-enzyme solidified layer shall comply with the provisions of Table 2-2:

(8) The maximum particle size of the subbase mixture shall not exceed 53mm; the maximum particle size of the base mixture shall not exceed 37.5mm.

(9) On-site investigation, select suitable raw materials for indoor tests, and determine the maximum dry density and optimal moisture content of the mixture. The mixing ratio range of the bio-enzyme mixture is:

Raw material test items and methods

Test Items	Material Name	Sampling	Instruments and test methods
Moisture content	Soil and grade ingredients	Test two samples before each use	Drying method, rapid tester, alcohol method
Liquid and plastic limit	Fine grained and soil below 0.5mm in grading	Test two samples for each type of soil before use and two samples for each batch of material during use.	joint determination of liquid-plastic limit
Crushing value	Gravel, crushed stone, etc.	Test two samples of each material before use and two samples of each batch of material during use	aggregate crushing value test
Density, setting time, stability and other basic properties	Cement	Two samples were measured during formulation design and construction. After each batch of material test two samples	Refer to relevant test specification
Particle Analysis	Soil and gradation	Test two samples for each type of soil before use and two samples for each batch of material in use	Screening method (water screening method for soil-bearing materials)
organic matter	Soil	Do this test if necessary.	organic matter content test

QUALITY REQUIREMENTS

(1) The construction methods of bio-enzyme road construction technology are divided into three types: road mixing method, centralized road mixing method and plant mixing method. Comprehensive consideration of road construction standards, site conditions and economy, select the appropriate construction method.

(2) Before the biological enzyme curing layer is officially started, the test section shall be paved, and the length of the test section shall be determined according to the site conditions. Through the paving of the test section of the bio-enzyme solidified layer, the following main items are determined:

① The proportion of raw materials used for construction.

② Loose spreading coefficient of material.

③ Determine the standard construction method:

a. Control of mixture quantity;

B. Mixture paving method and applicable machines and tools;

c. Appropriate mixing machinery, mixing method, mixing time and mixing times;

d. The increase and control method of the water content of the mixture;

e. Suitable machines and methods for leveling and shaping;

f. Selection and combination of compaction machinery, sequence, speed and number of times of compaction;

g. Coordination and coordination of mixing, transportation, spreading and rolling machinery;

H. the inspection method of compactness, and the minimum inspection quantity of each operation section is initially determined.

④ Determine the appropriate length of each operation section.

⑤ Determine the appropriate thickness of one paving.

⑥ By paving the test section of the bio-enzyme curing layer, the method of controlling the quantity of binding materials and mixing uniformity shall also be determined.

(3) The biological enzyme solidified layer is the main load-bearing structure. The biological enzyme mixture shall be matched according to the design formula, and the mixture shall be screened and the moisture content shall be inspected.

(4) The dilution ratio of biological enzyme depends on the amount of water required for the mixture. The amount of water added to the mixture shall not exceed the optimal moisture content of the mixture, and the ideal amount of water added shall be the optimal moisture content ~ the optimal moisture content + 2%.

(5) When spraying the biological enzyme solution, it should be sprayed evenly in multiple times to make the biological enzyme evenly distributed in the mixture. The prepared biological enzyme solution cannot be used overnight. In case of deterioration and failure, an appropriate enzyme solution should be prepared according to the daily workload.

(6) When using the road mixing method, special attention must be paid to the mixing depth. In the mixing process, the mixing depth must be strictly controlled to the top surface of the subgrade, and the plain soil interlayer must be avoided.

(7) In order to ensure the construction quality of the solidified layer shoulder, the solidified layer shall be properly made of super-wide cloth, and a wide enough shoulder shall be paved. Attention shall be paid to the elevation and size of the shoulder, the treatment of defects and the compaction of edges.

(8) During paving, attention should be paid to eliminate the segregation of coarse and fine grains, and it is required that all places are mixed evenly and have consistent color. Rolling shall be carried out in the order of light before heavy, static before vibration, two sides before middle, slow before fast, to reach the specified compaction degree. It is forbidden for the roller to turn around or brake suddenly on the road section that has been completed or is being rolled, so as not to damage the surface of the solidified soil layer.

(9) The construction shall be strictly organized, and the initial setting time of cement shall not be exceeded from mixing to the end of rolling.

(10) During curing, water shall be sprinkled after 4~6h after the rolling is completed according to the temperature conditions, and water shall be sprinkled at least three times a day in sunny weather to keep the surface of the biological enzyme solidified layer in a moist state, and the curing time shall not be less than 7d. After the construction of bio-enzyme solidified layer, light traffic can be opened, and heavy traffic can be opened after the end of health preservation. When the maintenance vehicle is running on the road, it is forbidden to brake or turn sharply.

(11) The quality requirements for the base and subbase of the bio-enzyme-cured pavement shall comply with the following table:

Detection items of biological enzyme solidified layer

Item Times	Inspection Items		Specified value or allowable deviation		Inspection method and frequency
			Grass-roots	Subbase
1	Compaction (%)	Representative value	97	97	Each operation section or more than 2000m, six times
2	Flatness (mm)		8	12	3m ruler: measure 2 places × 10 feet every 200m
3	Longitudinal elevation (mm)		5，-10	5，-15	Level gauge: measuring 4 sections per 200m
4	Width (mm)		Not less than design	Not less than design	Dipstick metering: measuring 4 sections per 200m
5	Cross slope (%)		±0.3	±0.3	Level gauge: measuring 4 sections per 200m
6	Deflection (0.01mm)		≤ 65	≤ 130	Inspection of left and right wheels every 20m
7	Midline deviation (mm)		50	50	Theodolite: measure 4 points every 200m, and add HY and YH points to the curve.
8	Strength (Mpa)		Meet the design requirements	Meet the design requirements	Prepare 1 set of test pieces per 2000m2

The performance and technical indicators are shown in the following table:

Various performance and technical indexes of base course and subbase course

Engineering category	Project	Frequency	Standard	Treatment measures when the requirements are not met
Base and subbase	Moisture content	It is observed that test at any time when abnormal	Optimum water content-2%,+ 1%	Dry in the air when it is too wet, and adjust the concentration of enzyme solution or sprinkle 1:1000 bio-enzyme dilute solution when it is too dry.
	Gradation	It is observed that test at any time when abnormal	Within the specified range	Investigate raw materials and revise site mix proportion as required
	Uniformity	Observe at any time	Uniform overall color, no material segregation	Supplementary mixing, locally adding missing aggregate
	degree of compaction	Each operation section or more than 2000m, six times.	More than 97%, or meet the design requirements	Continue rolling, curing rolling, and replace parts with high water content or poor materials.
	rebound deflection	Inspection of left and right wheels every 20m	Meet the design requirements	Check the subgrade bed and improve the compactness

The construction quality control of bio-enzyme solidified soil plays a vital role in the construction process. The construction quality control index and construction quality inspection index of the roadbed, bio-enzyme subbase and base of bio-enzyme soil solidified road construction technology provide the basis for the construction quality control and inspection of bio-enzyme solidified layer, which is of great significance to ensure the construction level and quality of bio-enzyme solidified soil.

 

Construction quality control requirements for 2. multi-component modified roller compacted cement concrete test road

1. Basic requirements for construction quality

1) The strength, physical properties and chemical composition of cement shall comply with the provisions of national standards and relevant specifications.

2) The aggregate, water, additive and joint sealant shall meet the requirements of design and construction specifications.

3) The construction mixture ratio shall be calculated according to the actual strength of cement measured on site, and the best mixture ratio shall be selected through tests.

4) The mixed fiber rubber powder cement mixture shall be uniform, free of white flowers, aggregate separation and clumping.

5) During paving, the paving thickness and flatness shall be strictly controlled to avoid segregation and be rolled to the required compactness.

6) The connection between the surface layer and other structures shall be smooth, the elevation of the rain gate shall be 5~8mm lower than that of the road surface according to the design, and there shall be no water accumulation at the edge of the road surface.

7) After the pavement is paved, it shall be cured according to the construction requirements.

2. Pavement quality inspection index

After the construction of the multi-component multi-modified roller compacted cement concrete test section is completed, the quality inspection of the multi-component multi-modified roller compacted cement concrete test section is carried out, mainly including strength, structural depth, anti-slip value, flatness and actual paving effect of the road surface as shown in the table.

Measurement Items of Multivariate and Multiple Modified Roller Compacted Cement Concrete

Item Times	Inspection Items		Specified value or allowable deviation	Inspection method and frequency
1	Compaction (%)	Representative value	More than 96%	Sand filling method: measuring 2 points per 200 meters per lane
2	Thickness (mm)	Representative value	-5	Gradienter: measuring 4 sections per 200 m
		acceptable value	-10
3	Deflection (0.01mm)		45	Beckman beam or automatic deflectometer: 80 points per 1km
4	Longitudinal elevation (mm)		±15	Gradienter: measuring 4 sections per 200 m
5	Width (mm)		±20	Meter ruler: 4 points per 200 meters
6	Flatness (mm)		10	3 m ruler: 2 × 10 feet per 200 m
7	Cross slope (%)		±0.5	Gradienter: measuring 4 sections per 200 m
8	Modulus of resilience (MPa)		≥ 900	PFWD method every 200 meters
9	Bending strength of rolled specimen of standard size (MPa)		≥ 6.5	Roller test piece of modified die