一、概述：

采用落砂法評價被測樣品表面的耐損磨性能，適用于A1類，A2類突起路標。A3類可參照使用。

I. Overview:

The falling sａnd method is used to evaluate the wear resistance of the tested sample surface, which is suitable for A1 and A2 protruding road signs. Class A3 can be used by reference.

二、測試裝置構(gòu)成：

◆測試裝置由垂直導砂管，校正漏斗，過濾網(wǎng)，樣品架和砂子收集器組成。導砂管：可采用內(nèi)徑不小于150MM內(nèi)壁光滑的實壁塑料管組成，長度為2850MM,導砂管的不垂直度不大于0.2°。

◆校正漏斗：校正漏斗的上口尺寸為120MM×40MM,高度100MM,四面坡角45°。上口四邊應(yīng)平直，尖銳，保證落在口邊上的砂子落入斗內(nèi)時不改變方向。該漏斗的作用是保證直接落入口內(nèi)的沙子不偏離地，盡可能垂直地沖擊突起路標，而落到口外的沙子被偏離到斗外，不能沖擊突起路標。校正漏斗應(yīng)能上下，左右，前后移動，方便調(diào)整通過漏斗的砂量和均勻性。

◆過濾網(wǎng)：過濾網(wǎng)位于導砂管的上部，網(wǎng)孔尺寸為大于850UM的標準網(wǎng)。該過網(wǎng)的作用一是確立落砂的起始點，二是限制落砂的流速。要求落砂離網(wǎng)的距離不應(yīng)大于30MM。

◆樣品架：用于將被測樣品夾持穩(wěn)固，使樣品的基底面保持垂直，方便地將樣品與導砂管，校正漏斗對中，能自由調(diào)整被測樣品的高度使其上邊沿與漏斗上口保持不大于150MM，并能調(diào)整水平方向使樣品逆反射面底邊前沿與漏斗長邊方向平行。樣品架不應(yīng)阻擋落砂的自由流動。

◆收集器：可用1只300MM×500MM的搪瓷托盤，或其他容器。為了防止落入校正漏斗的砂子濺出或外部的砂子濺入，可用與漏斗下口相同的軟布罩將漏斗下口空間封圍。

2. Test device composition:

◆The test device consists of a vertical sａnd guide pipe, a calibration funnel, a filter screen, a sample holder and a sａnd collector. Sａnd guide pipe: It can be composed of a solid-walled plastic pipe with an inner diameter of not less than 150MM and a smooth inner wall. The length is 2850MM. The non-verticality of the sａnd guide pipe is not more than 0.2°.

◆Calibration funnel: The upper mouth size of the calibration funnel is 120MM×40MM, the height is 100MM, and the four-sided slope angle is 45°. The four sides of the upper mouth should be straight and sharp to ensure that the sａnd falling on the edge of the mouth does not change its direction when it falls into the bucket. The function of the funnel is to ensure that the sａnd directly falling into the mouth does not deviate from the ground and hits the protruding road sign as vertically as possible, while the sａnd falling outside the mouth is deviated to the outside of the bucket and cannot hit the protruding road sign. The calibration funnel should be able to move up and down, left and right, and back and forth to facilitate adjustment of the amount and uniformity of sａnd passing through the funnel.

◆Filter mesh: The filter mesh is located on the upper part of the sａnd guide pipe, and the mesh size is a standard mesh larger than 850UM. The function of the net is to establish the starting point of falling sand, and the other is to limit the flow rate of falling sand. It is required that the distance between falling sａnd and the net should not be greater than 30mm.

◆Sample rack: It is used to hold the tested sample firmly, keep the base surface of the sample vertical, and conveniently center the sample with the sａnd guide tube and the calibration funnel. The height of the tested sample can be adjusted freely to make the upper edge of the funnel and the funnel. Keep the upper mouth no larger than 150mm, and adjust the horizontal direction so that the front edge of the bottom edge of the sample retroreflective surface is parallel to the long side of the funnel. The sample holder should not block the free flow of falling sand.

◆ Collector: 1 300MM×500MM enamel tray or other containers can be used. In order to prevent the sａnd falling into the calibration funnel from splashing or external sａnd from splashing in, the lower mouth space of the funnel can be enclosed by the same soft cloth cover as the lower mouth of the funnel.

三、試驗步驟：

◆將設(shè)備和被測樣品安裝調(diào)整到位，并保證導砂管上部至被測樣品底面上邊沿的距離為3.00M±0.03M。

◆取足夠用的試驗用砂，以0.4KG/MIN―1.0KG/MIN的速度均勻落入導砂管上部的過濾網(wǎng)上，注意觀察落砂沖擊樣品的均勻性和部位，并經(jīng)常按照B.6的方法校準試驗裝置的均勻性。

◆收集通過校正漏斗的砂子并稱重，稱重的砂子包括撞擊到樣品及樣品架上濺射到外部的砂子，但不含沒有通過漏斗的部分，當發(fā)現(xiàn)收集的砂量不滿足2.5KG±0.050KG要求時，應(yīng)按照B.6的方法對試驗裝置進行校準。

◆取下被測樣品，用軟布清潔后，測量被沖擊逆反射面的發(fā)光強度系數(shù)。

◆將用過的試驗砂棄掉，試驗用砂每個試驗只用1次，不應(yīng)重復使用。

◆測試裝置校準

落砂應(yīng)均勻地通過校正漏斗，其均勻性通過在漏斗下突起路標的位置和高度上放置至少10個口徑約為10MM的小瓶來驗證。當足夠的沙子下落通過漏斗時，至少有1個小瓶收集到至少5G的砂子，收集最少的小瓶中沙子重量至少達到收集最多的小瓶中沙子重量的75％為測試裝置合格。在確定裝置的流動穩(wěn)定性之后，視需要通過調(diào)整漏斗的上下和總用砂量來校準其均勻性和通過漏斗的砂量。

◆ 測試裝置的修正

當被測突起路標底邊大于100MM時應(yīng)對整個裝置進行修正，假設(shè)被測突起路標底邊為（100+X）MM,則修正內(nèi)容如下：

校正漏斗的上口長邊為（120+X）MM;

導砂管的內(nèi)徑應(yīng)至少（150+X）MM;

c) 通過校正漏斗的試驗砂的質(zhì)量應(yīng)為(2.5+0.020 8X)KG,允差±2％;

d) 通過漏斗落砂的流速應(yīng)保持在（0.4+X/300）KG/MIN―(1+X/120)KG/MIN

3. Test steps:

◆Install and adjust the equipment and the tested sample in place, and ensure that the distance from the top of the sａnd guide pipe to the edge of the bottom of the tested sample is 3.00M±0.03M.

◆Take enough test sａnd and drop it evenly on the filter screen on the upper part of the sａnd guide tube at a speed of 0.4KG/MIN-1.0KG/MIN. Pay attention to the uniformity and position of the sample impacted by the falling sand, and always follow B.6 The method to calibrate the uniformity of the test device.

◆Collect and weigh the sａnd that has passed the calibration funnel. The weighed sａnd includes the sａnd that hits the sample and the sample holder is splashed to the outside, but does not include the part that has not passed through the funnel. When it is found that the amount of sａnd collected does not meet 2.5KG± When 0.050KG is required, the test device should be calibrated in accordance with the method in B.6.

◆Remove the tested sample, clean it with a soft cloth, and measure the luminous intensity coefficient of the impacted retroreflective surface.

◆Discard the used test sand. The test sａnd should only be used once for each test and should not be reused.

◆Test device calibration

The falling sａnd should pass through the calibration funnel uniformly, and its uniformity is verified by placing at least 10 vials with a diameter of about 10MM at the position and height of the protruding road signs under the funnel. When enough sａnd falls through the funnel, at least one vial collects at least 5G of sand, and the weight of the sａnd in the least collected vial reaches at least 75% of the weight of the sａnd in the most collected vial to qualify the test device. After determining the flow stability of the device, adjust its uniformity and the amount of sａnd passing through the funnel by adjusting the top and bottom of the funnel and the total amount of sａnd as needed.

◆ Modification of test equipment

When the bottom side of the measured raised road sign is greater than 100MM, the entire device should be corrected. Assuming that the bottom side of the measured raised road sign is (100+X)MM, the correction content is as follows:

The long side of the upper mouth of the correction funnel is (120+X) MM;

The inner diameter of the sａnd guide pipe should be at least (150+X) MM;

c) The quality of the test sａnd passing the calibration funnel should be (2.5+0.020 8X) KG, with a tolerance of ± 2%;

d) The flow rate of sａnd falling through the funnel should be maintained at (0.4+X/300)KG/MIN―(1+X/120)KG/MIN

四、注意事項：

◆試驗環(huán)境

溫度23°C± 2°C,相對濕度（50±25）％。

◆測試用砂

試驗用砂應(yīng)使用二氧化硅含量的天然石英砂。

這種石英砂的顆粒分布應(yīng)該滿足如下要求：在經(jīng)過10MIN的聯(lián)系搖篩之后，不超過總量的10％保留在20號篩（850UM）上，不超過總重的10％漏過30號篩（600UM）.

注：在ASTM D 4280-2004中使用位于美國中部St,Peters或Jordan的砂巖沈積砂。

Four, matters needing attention:

◆Test environment

Temperature 23°C± 2°C, relative humidity (50±25)%.

◆Sａnd for testing

The test sａnd should use natural quartz sａnd with extremely high silica content.

The particle distribution of this kind of quartz sａnd should meet the following requirements: after 10 MIN, no more than 10% of the total weight is retained on the No. 20 sieve (850 UM), and no more than 10% of the total weight is passed through the No. 30 sieve. (600UM).

Note: ASTM D 4280-2004 specifies the use of sandstone sedimentary sａnd located in St, Peters or Jordan in the central United States.