Before backfilling, the backfill materials shall be taken from the site for compaction test, and the soil samples taken shall be representative.
Those less than the above quantity shall be regarded as one batch.
2) Cement entrusted inspection samples must take each ex factory cement number as a sampling unit, and there shall be no mixed sampling of more than two ex factory numbers.
(Stone: 100kg, sand: 50kg) 3) if the inspection is unqualified, re sampling shall be carried out.
3、 Standard for foundation backfill sampling: Standard for geotechnical test methods (2007 Edition) GB / t50123-1999 (2007 Edition) (implemented on October 1, 1999, currently effective); Standard for quality inspection and evaluation of Highway Engineering Volume I civil engineering jtgf80 / 1-2004 (implemented on January 1, 2005, currently valid) Note: Standard for quality inspection and evaluation of Highway Engineering Volume I civil engineering jtgf80 / 1-2017 will be implemented on May 1, 2018.
Bagged cement and bulk cement shall be numbered and sampled respectively.
Then, for sand, approximately 8 equal parts are taken from each part to form a group of samples.
Rules for cement sampling and sample delivery 1) first, it is necessary to know whether the manufacturer of the purchased cement has a product production license.
When the capacity of bulk cement transportation vehicles exceeds the tonnage of the factory number specified by the factory, the quantity of this number is allowed to exceed the tonnage specified for sampling.
The factory number of cement is specified as a and 200 according to the annual production capacity × More than 104t and no more than 4000t are one number; B、120 × 104t～200 × 104t, no more than 2400t is a number; C、60 × 104t～120 × 104t, no more than 1000t is a number; D、30 × 104t～60 × 104t, no more than 600t is a number; E、10 × 104t～30 × 104t, no more than 400t is a number; F、10 × Below 104t and no more than 200t are one number.
One group is selected for other 50m2 ~ 200m2..
1、 Standard for cement witness sampling: General Portland cement (National Standard No.
Each number is a sampling unit.
4) The entrusting unit must fill in the inspection entrustment form item by item, such as cement manufacturer name, trademark, cement variety, strength grade, factory number or factory date, project name, full set of physical inspection items, etc.
Note: Cement sampling shall be accompanied by corresponding cement factory certificate.
2) When there is doubt about the quality of cement in use or the cement leaves the factory for more than three months (fast hardening portland cement for more than one month), it shall be re inspected and used according to the re inspection results.
6) Imported cement shall be processed according to the above requirements.
Indoor backfilling: ditch and foundation, one group for each layer of 20m2 ~ 50m2; D.
3) Cement samples must be collected in equal quantities at different parts of the same number.
For stones, approximately 15 equal parts are taken from each part (obtained from five different parts evenly distributed at the top, middle and bottom of the pile) to form a group of samples.
The sampling amount of compactness shall meet the following requirements.
Cement sampling regulations 1) cement shall be numbered and sampled according to the same variety and strength grade before delivery.
Remove the surface layer of the sampling part before sampling.
The sampling point shall be at least 20 points.
Standard for sampling of sand and stone: Pebble and crushed stone for construction GB / t14685-2011 (implemented on February 1, 2012, currently valid); Construction sand GB / t14684-2011 (implemented on February 1, 2012, valid at present) 1) for sand and stone transported by large tools, 400m3 or 600t shall be taken as an acceptance batch.
(clay: 30kg; gravel soil and graded sand: 50kg) 2.
For those transported by small tools, 200m3 or 300t shall be taken as an acceptance batch.
Site leveling: one group is selected for each layer of 100m2 ~ 400m2; B.
When the quality of sand and gravel is relatively stable and the feeding amount is large, 1000t can be used as an acceptance batch.
Separate foundation pit: 20m2 ~ 50m2, take one group, and not less than one group; C.
5) The cement shall be reinspected before it is ready for use if the ex factory date is more than three months.
2) When sampling in the stockpile, the sampling parts shall be evenly distributed.
1 Amendment) GB175-2007 / xg1-2009 (implemented on September 1, 2009, currently effective); Nomenclature, definitions and terms of cement GB / t4131-2014 (implemented on February 1, 2015 and currently effective); Cement sampling method gb12573-2008 (implemented on August 1, 2008, effective at present) 1.
Double re inspection shall be conducted for unqualified items.
If one sample still fails to meet the standard requirements, it shall be treated as nonconforming product.
After mixing evenly, they shall be packed in moisture-proof containers with a weight of not less than 12 kg.
The cement used for decoration shall be tested for stability.