CN1062789A - The method of measuring and calculating mortar cubic compressive strength on masonry - Google Patents
The method of measuring and calculating mortar cubic compressive strength on masonry Download PDFInfo
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- CN1062789A CN1062789A CN 90110230 CN90110230A CN1062789A CN 1062789 A CN1062789 A CN 1062789A CN 90110230 CN90110230 CN 90110230 CN 90110230 A CN90110230 A CN 90110230A CN 1062789 A CN1062789 A CN 1062789A
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Abstract
The present invention relates to a kind of measuring method of bonding mortar strength in the building engineering field, particularly directly on masonry, calculate a kind of method of mortar cubic compressive strength.By many groups masonry mortar sheet shearing strength being tested the test that reaches with the mortar test cube compressive strength of condition, set up the mathematical relation between mortar cubic compressive strength and the mortar sheet shearing strength, as long as measure the shearing strength that directly on masonry, separates the mortar sheet, just can try to achieve the cubic compressive strength of this mortar.
Description
The present invention relates to a kind of measuring method of bonding mortar strength in the building engineering field, particularly directly on masonry, calculate a kind of method of mortar cubic compressive strength.
The existing technical manual GBJ203-83 of country " masonry construction and acceptance specification " regulation, when building masonry by laying bricks or stones, making one group of (six) length of side is the mortar test cube of 7.07cm, after the method maintenance in accordance with regulations, whether meet design requirement with the cubic compressive strength of determining mortar through test.
Because the curing condition of test block is different with the curing condition of mortar in the masonry, proportioning also may be different with the degree of stirring, thereby the compressive strength of mortar specimen can not be represented the intensity of mortar in the masonry fully.Old room maintenance and reinforcement simultaneously, authentication process, the reinforcement of construction work after the earthquake, the processing of accident resulting from poor quality of projects all needs to know the intensity of mortar in the masonry.Although the compressive strength of mortar specimen can not be represented the intensity of mortar in the masonry fully, test block this moment does not have yet, and country does not stipulate legal method use yet.
Each units concerned has studied some method of testings in succession for this reason, although these methods have nothing in common with each other, summarizes and gets up can be divided into two big classes.The first kind is the mechanical index of test masonry, the corresponding computing formula inverse mortar cubic compressive strength that utilizes design specifications to provide; Second class is directly in masonry on the screed or the mortar on-chip testing of peeling off.
The method of testing that belongs to the first kind has:
1) resistance to compression examination body method, this method is that the taking-up volume is 37 * 49 * 100cm on masonry
3The examination body, test its compressive strength, the label of brick is known in the masonry, formula inverse mortar cubic compressive strength according to the existing design specifications of masonry structure provides makes in this way, generally will get 3 examination bodies, time-consuming, effort, and destroyed the one-piece construction of brick setting, simultaneously because the influence of factors such as the plumpness of mortar, building method makes measuring accuracy lower.
2) single brick tension, the shearing resistance method, this method is by antidetonation institute of Chinese Research Institute for Building Sciences, " industry and covil construction seismic hardening technical measures " book that nine units such as Institute of Architectural Design ﹠ Research, Tianjin University compile in collaboration with provides, the tension method, the shearing resistance method is by tensile strength of testing single brick horizontal mortar joint or shearing strength, straight joint bending and tensile strength or the full seam shear resisting strength formula inverse mortar compressive strength of utilizing design specifications to provide, these two kinds of methods have overcome the bulky deficiency of resistance to compression examination body method, but exist the problem that produces disturbance when picking seam, the problem that influences that also has masonry quality, it is also difficult accurately to get rid of the not full influence of mortar simultaneously.
Belong to having of the second class testing method:
1) rebound method: this method utilizes cube compressive strength of mortar and the correlativity between its hardness to set up the strong curve of survey.Rebound method at first is applied to concrete and surveys strong, what kind of can provide closely knit, smooth resilience face because the screed in the brick setting does not resemble concrete, and the hardness of screed and water percentage, carbonization are whether, carbonation depth is relevant, influence factor is a lot, measuring accuracy is relatively poor, " ... its error is in ± 30% " write in instructions as the producer that produces reisilometer.
2) some lotus method: Chinese Research Institute for Building Sciences is introduced in this institute " experimental study of brick setting mortar strength " some lotus " method of testing " report, this method applies on the mortar sheet concentrated " some lotus ", adding butt is that interior angle is 60 ° a cone, the head of awl is the intercept sphere of radius R=5mm, the about 3mm of height that intercepts ball, whole cone adds butt and highly is 30mm, during test, measure maximum " some lotus " value that the mortar sheet bears, according to the compressive strength of the computing formula calculation testing piece between " some lotus " value of having set up and the standard compressive strength.
It is little that " some lotus " strength test method has sample dimensions, to the obvious advantage of the less demanding grade of test specimen load-bearing surface evenness, but with regard to the experimental formula between mortar sheet test specimen " some lotus " value and the intensity
(P)/(（0.05R+1）[0.03t（0.01t+1）+0.4]) ＝af
b b+C
In the formula: P-point lotus value
f
b-mortar compressive strength
R-point lotus application point is to the minor increment at edge.
T-mortar sheet thickness
Analyze, computing formula is failed and " some lotus " intensity opening relationships, but has set up relation with mortar sheet member and main geometric.The relevant test figure that is provided by the research report of this method is calculated in addition, and the average relative error of this method is ± 20.3%.
As previously mentioned, domestic existing method of testing is because of the influence of various factors, and accuracy is lower, the purpose of this invention is to provide a kind ofly directly to take a sample on the horizontal mortar joint in masonry, measure the method for the cubic compressive strength of mortar in the masonry, can improve accuracy of test and method and be simple and easy to realize.
Method provided by the invention is:
Measure the shearing strength of test specimen masonry medium sand lodicule, measure the cubic compressive strength with this mortar sheet test cube in the same condition simultaneously, utilize correlativity between them to set up mathematical relation between mortar cubic compressive strength and the mortar sheet shearing strength; After measure the shearing strength of peeling off the mortar sheet on the masonry, can utilize the relationship of being set up to calculate the cubical compressive strength of mortar.
Above-mentioned mathematical relation is:
f
1 b＝k（ (τ)/(a+bτ) ）
c
In the formula: f
1 b-mortar cubic compressive strength MPa
The shearing strength MPa of τ-mortar sheet
K, a, the certain constant of b, c-
The invention has the advantages that:
Show that by a large amount of test figures exist good correlativity between mortar cubic compressive strength and the mortar sheet shearing strength, the index of correlation reaches 0.99.Average same error is ± 6.3%, and the relative standard deviation is 7.65%, and measuring accuracy is higher, satisfies requirement of engineering.Test shows that mortar sheet physical dimension does not make significant difference to test result, convenient test, and this method is simple simultaneously, is convenient to promote the use of.
The embodiment explanation:
(1) starting material are prepared
At first use Portland cement, maximum particle diameter mostly is the medium sand of 2.5mm, and pure lime cream is prepared the mixed mortar of different labels by weight, and mortar stirs with artificial, adopts long-time many people repeatedly to stir, and guarantees the homogeneity of mortar.
Use machine common brick, it is moistening to water in advance, and water percentage is 10%-15%.
Before starting material are made test specimen, put in 2 days at least in advance indoor, to guarantee mortar and the same condition of test block in the test specimen.
(2) test specimen is made
A. two brick test specimens that close, each proportioning is made 6 test specimens.
With two brick closing, the length of side when making different proportioning with die trial simultaneously is the mortar test cube of 7.07cm with mixed mortar.
B. two bricks are isolated the test specimen of bonding, and each proportioning is made 6 test specimens.
At the l Water Paper of the drenched good water permeability of brick upper berth, end one deck water,, and shakeout substantially earlier,, then face brick is built on l Water Paper again at mortar upper berth one deck l Water Paper at l Water Paper upper berth one layer mixed mortar.The length of side when also making different proportioning with die trial simultaneously is the mortar test cube of 7.07cm.
(3) maintenance
Test block and the brick test specimen that closes before the demoulding of mortar cube are put together, and natural curing in room air after the test block demoulding, is put test block and closed on the test specimen in brick, hide with Polypropylence Sheet, and natural curing in the room air is until test.
Isolate the test specimen of bonding for two bricks, after making finishes, spent three hours, face brick is taken away, spend 24 hours, mortar sheet two sides l Water Paper is removed in the test block demoulding, and test block and mortar sheet are placed indoor maintenance with being placed in the polybag.
(4) test
To a class test specimen, knock two bricks open, peel off the mortar sheet, intercept suitable mortar sheet piece, to b class test specimen, also intercept suitable mortar sheet piece.With testing tool the mortar sheet is cut, obtained the shear resistance of mortar sheet.The compressive strength of the mortar of pressure testing simultaneously test cube, test data with the compressive strength of the shear resistance of the corresponding mortar sheet of each group and this mortar specimen is determined each point coordinate in coordinate system, back each point is linked to be curve, according to the curve form mathematical statistic method, determine basic relationship, the relationship of determining in the present embodiment is:
f
1 b＝k（ (τ)/(a+bτ) ）
c
In the formula: f
1 b-sand icecube body compressive strength MPa
The shearing strength MPa of τ-mortar sheet
K, a, the certain constant of b, c-
By to from 6 kinds of different grades of mortar of 0.68MPa-15.17MPa, organize the test data (seeing additional materials) of multi-disc test specimen more, the constant K, a, b, the c that extrapolate in the formula are respectively 0.059-0.89,0.0478,0.0392,1.752.Their value is relevant with factors such as the instrument of testing shear resistance, scaling method, local material, sand thicknesses.
Claims (2)
1, a kind of method of calculating the mortar cubic compressive strength on masonry is characterized in that:
A. measure the shearing strength of masonry medium sand lodicule, measure simultaneously and the cubic compressive strength of this mortar sheet, utilize correlativity between them to set up mathematical relation between mortar cubic compressive strength and the mortar sheet shearing strength with the condition mortar specimen;
B. measure the shearing strength of the mortar sheet of directly on masonry, peeling off after, can utilize the relationship of being set up to calculate the cubical compressive strength of mortar.
2, a kind of method according to claim 1 is characterized in that: the mathematical relation between mortar cubic compressive strength and the mortar sheet shearing strength is
f
1 b＝K（τ/a+bτ）
c
In the formula: f
1 b-mortar cubic compressive strength units MPa
The shearing strength MPa of τ-mortar sheet
K, a, the certain constant of b, c-
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90110230 CN1062789A (en) | 1990-12-27 | 1990-12-27 | The method of measuring and calculating mortar cubic compressive strength on masonry |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90110230 CN1062789A (en) | 1990-12-27 | 1990-12-27 | The method of measuring and calculating mortar cubic compressive strength on masonry |
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| Publication Number | Publication Date |
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| CN1062789A true CN1062789A (en) | 1992-07-15 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90110230 Pending CN1062789A (en) | 1990-12-27 | 1990-12-27 | The method of measuring and calculating mortar cubic compressive strength on masonry |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1067766C (en) * | 1992-09-30 | 2001-06-27 | 宁夏回族自治区建筑工程研究所 | Directly measuring bonding mortar strength method and equipment |
| CN104502204A (en) * | 2014-12-12 | 2015-04-08 | 广西科技大学 | Method for testing shear resistance of urban sludge sintered shale solid brick masonry |
| CN109163984A (en) * | 2018-07-04 | 2019-01-08 | 无锡市房屋安全管理处（无锡市房产监察支队无锡市房屋安全鉴定中心） | The calculation method of the shearing strength of masonry structure component under a kind of different water cut |
-
1990
- 1990-12-27 CN CN 90110230 patent/CN1062789A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1067766C (en) * | 1992-09-30 | 2001-06-27 | 宁夏回族自治区建筑工程研究所 | Directly measuring bonding mortar strength method and equipment |
| CN104502204A (en) * | 2014-12-12 | 2015-04-08 | 广西科技大学 | Method for testing shear resistance of urban sludge sintered shale solid brick masonry |
| CN109163984A (en) * | 2018-07-04 | 2019-01-08 | 无锡市房屋安全管理处（无锡市房产监察支队无锡市房屋安全鉴定中心） | The calculation method of the shearing strength of masonry structure component under a kind of different water cut |
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