{"id":872,"date":"2020-02-13T14:57:17","date_gmt":"2020-02-13T14:57:17","guid":{"rendered":"https:\/\/seismicconsolidation.com\/?p=872"},"modified":"2020-02-13T14:57:17","modified_gmt":"2020-02-13T14:57:17","slug":"determination-of-aggregate-impact-value-aiv-of-given-aggregate-sample-bs-812","status":"publish","type":"post","link":"https:\/\/seismicconsolidation.com\/determination-of-aggregate-impact-value-aiv-of-given-aggregate-sample-bs-812\/","title":{"rendered":"Determination of aggregate impact value (AIV) of given aggregate sample (BS-812)"},"content":{"rendered":"<p><strong>Lab 3:<\/strong><\/p>\n<p><strong>Determination of aggregate impact value (AIV) of given aggregate sample<\/strong><\/p>\n<p><strong>(BS-812)<\/strong><\/p>\n<p><strong><u>Significance:<\/u><\/strong><\/p>\n<ul>\n<li>Aggregates used in the construction of roads should be strong enough to resist crushing under traffic wheel loads.<\/li>\n<li>It gives relative measure of the resistance of an aggregate to sudden shock or impact.<\/li>\n<li>Increase in impact value will indicate reduction in strength of material.<\/li>\n<\/ul>\n<p><strong><u>Apparatus:<\/u><\/strong><\/p>\n<ol>\n<li>Aggregates passing sieve \u00bd\u201d and retained on 3\/8\u201d from different sources.<\/li>\n<li>Aggregate impact value apparatus<\/li>\n<li>Weighing balance<\/li>\n<li>Tamping rod<\/li>\n<li>Sieve # 7 (opening 2.83 mm)<\/li>\n<li>Brush with stiff bristles<\/li>\n<li>Drying Oven<\/li>\n<li>Metal try of known mass<\/li>\n<\/ol>\n<p><strong>Specifications of impact value apparatus:<\/strong><\/p>\n<p>Cylindrical container having internal diameter of 75 mm and depth of 50mm<\/p>\n<p>Weight of hammer = 13.5 \u2013 14 kg<\/p>\n<p>Height of fall of hammer = 15\u201d<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter size-full wp-image-873\" src=\"https:\/\/seismicconsolidation.com\/wp-content\/uploads\/2020\/02\/Picture4.png\" alt=\"\" width=\"418\" height=\"498\" srcset=\"https:\/\/seismicconsolidation.com\/wp-content\/uploads\/2020\/02\/Picture4.png 418w, https:\/\/seismicconsolidation.com\/wp-content\/uploads\/2020\/02\/Picture4-252x300.png 252w, https:\/\/seismicconsolidation.com\/wp-content\/uploads\/2020\/02\/Picture4-300x357.png 300w\" sizes=\"(max-width: 418px) 100vw, 418px\" \/><\/p>\n<table width=\"100%\">\n<tbody>\n<tr>\n<td>\n<p style=\"text-align: center;\"><strong>Impact Value Apparatus with its Parts<\/strong><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong><u>Related theory:<\/u><\/strong><\/p>\n<p><strong>Types of tests performed on aggregates:<\/strong><\/p>\n<ol>\n<li>Impact value test<\/li>\n<li>Loss Angeles abrasion test<\/li>\n<li>Aggregate crushing value<\/li>\n<li>Soundness test<\/li>\n<li>Moisture content of aggregate<\/li>\n<li>Relative density and water absorption<\/li>\n<li>Sieve tests<\/li>\n<li>Flakiness index<\/li>\n<\/ol>\n<p><strong>Aggregate Impact value:<\/strong><\/p>\n<p>It is the % of fine material which is crushed after the application of load w.r.t. total weight of material.<\/p>\n<p><strong>Test specifications: <\/strong><\/p>\n<p>The test sample shall consist of aggregates which passes through \u00bd in B.S. test sieve and is retained on a 3\/8 in B.S. test sieve.<\/p>\n<p>The aggregate comprising the test sample should be dried in an oven for a period of four hours at a temperature of 105-110 <sup>0<\/sup>C and cooled.<\/p>\n<p><strong><u>Procedure: (Dry Condition)<\/u><\/strong><\/p>\n<ul>\n<li>Rest the impact machine, without wedging or packing, upon the level plate, block or floor, so that it is rigid and hammer guide columns are vertical<\/li>\n<li>Take oven dried sample that passes through sieve \u00bd\u201d and is retained on sieve 3\/8\u201d<\/li>\n<li>Place the sample in the cylindrical container of aggregate impact value apparatus and weigh it. Suppose this value is W<\/li>\n<li>Remove the sample from container in clean tray.<\/li>\n<li>Place the sample in cylindrical container of aggregate impact value apparatus in 3 layers.<\/li>\n<li>Each layer must be given 25 no. of blows<\/li>\n<li>Each blow being delivered at an interval of not less than 1s<\/li>\n<li>The hammer should be fall freely for about 15\u201d<\/li>\n<li>Remove the crushed aggregate by holding the cylinder over a clean tray and hammering on the outside with the rubber mallet until the particles are sufficiently disturbed to enable the mass of specimen to fall freely on tray.<\/li>\n<li>Transfer fine particles adhering to the inside of the cup and the underside of the hammer to the tray by means of the stiff bristle brush.<\/li>\n<li>Sieve the whole of specimen in the tray on the 2.36 mm test sieve until no further significand amount passes during a further period of 1 min.<\/li>\n<li>Weigh the mass that is passed as W<sub>2 <\/sub>and that is retained as W<\/li>\n<li>Now, if total mass differs from the initial mass W<sub>1<\/sub> by more than 1 g, discard the result and test a further specimen.<\/li>\n<li>Repeat the same procedure for the other samples and note the readings.<\/li>\n<li>Find the aggregate impact value from the formula given below:<\/li>\n<\/ul>\n<p style=\"text-align: center;\">\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>A<\/mi><mi>I<\/mi><mi>V<\/mi><mo>=<\/mo><msub><mi>W<\/mi><mn>2<\/mn><\/msub><mo>\/<\/mo><msub><mi>W<\/mi><mn>1<\/mn><\/msub><mo>&#215;<\/mo><mn>100<\/mn><\/math>\n<\/p>\n<p>where, W<sub>1<\/sub> is the total mass of sample<\/p>\n<p>W<sub>2 <\/sub>is the mass that passes sieve # 7<\/p>\n<p><strong><u>Observations and calculations<\/u><\/strong><\/p>\n<table width=\"629\">\n<tbody>\n<tr>\n<td style=\"width: 58px;\"><strong>Sr. no.<\/strong><\/td>\n<td style=\"width: 73px;\"><strong>Sample Source<\/strong><\/td>\n<td style=\"width: 101px;\"><strong>Total weight of sample (W<sub>1<\/sub>)<\/strong><\/td>\n<td style=\"width: 126px;\"><strong>Fraction passing sieve # 7 (W<sub>2<\/sub>)<\/strong><\/td>\n<td style=\"width: 123px;\"><strong>Fraction retained on sieve # 7 (W<sub>3<\/sub>)<\/strong><\/td>\n<td style=\"width: 108px;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58px;\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 73px;\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 101px;\"><strong>gm<\/strong><\/td>\n<td style=\"width: 126px;\"><strong>gm<\/strong><\/td>\n<td style=\"width: 123px;\"><strong>gm<\/strong><\/td>\n<td style=\"width: 108px;\"><strong>%<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58px;\"><strong>1<\/strong><\/td>\n<td style=\"width: 73px;\">Margalla<\/td>\n<td style=\"width: 101px;\">365<\/td>\n<td style=\"width: 126px;\">53<\/td>\n<td style=\"width: 123px;\">312<\/td>\n<td style=\"width: 108px;\">14.52<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58px;\"><strong>2<\/strong><\/td>\n<td style=\"width: 73px;\">Margalla<\/td>\n<td style=\"width: 101px;\">353<\/td>\n<td style=\"width: 126px;\">50<\/td>\n<td style=\"width: 123px;\">303<\/td>\n<td style=\"width: 108px;\">14.16<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58px;\"><strong>3<\/strong><\/td>\n<td style=\"width: 73px;\">Sargodha<\/td>\n<td style=\"width: 101px;\">341<\/td>\n<td style=\"width: 126px;\">37<\/td>\n<td style=\"width: 123px;\">304<\/td>\n<td style=\"width: 108px;\">10.85<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58px;\"><strong>4<\/strong><\/td>\n<td style=\"width: 73px;\">Sargodha<\/td>\n<td style=\"width: 101px;\">372<\/td>\n<td style=\"width: 126px;\">45<\/td>\n<td style=\"width: 123px;\">327<\/td>\n<td style=\"width: 108px;\">12.10<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p><strong><u>Precautions:<\/u><\/strong><\/p>\n<ul>\n<li>Care should be taken while giving blows with hammer.<\/li>\n<li>Aggregates should be oven dried.<\/li>\n<li>The mass should be noted nearest to 0.1 g.<\/li>\n<li>The time interval between the blows should not be less than 1s.<\/li>\n<\/ul>\n<p><strong><u>Comments:<\/u><\/strong><\/p>\n<p>The aggregates are classified on the basis of their impact value as<\/p>\n<table>\n<tbody>\n<tr>\n<td width=\"169\"><strong>Impact Value<\/strong><\/td>\n<td width=\"203\"><strong>Classification<\/strong><\/td>\n<\/tr>\n<tr>\n<td width=\"169\">&lt;10%<\/td>\n<td width=\"203\">Exceptionally strong<\/td>\n<\/tr>\n<tr>\n<td width=\"169\">10 \u2013 20%<\/td>\n<td width=\"203\">Strong<\/td>\n<\/tr>\n<tr>\n<td width=\"169\">20 \u2013 30%<\/td>\n<td width=\"203\">Satisfactory<\/td>\n<\/tr>\n<tr>\n<td width=\"169\">&gt;30<\/td>\n<td width=\"203\">Weak<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p>From the above classification, the given aggregate samples can be classified as <strong>Strong Aggregates <\/strong>because their respective impact values are in the range 10 to 20%<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Lab 3: Determination of aggregate impact value (AIV) of given aggregate sample (BS-812) Significance: Aggregates used in the construction of roads should be strong enough to resist crushing under traffic wheel loads. It gives relative measure of the resistance of an aggregate to sudden shock or impact. Increase in impact value will indicate reduction in&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[113],"tags":[116],"_links":{"self":[{"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/posts\/872"}],"collection":[{"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/comments?post=872"}],"version-history":[{"count":1,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/posts\/872\/revisions"}],"predecessor-version":[{"id":874,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/posts\/872\/revisions\/874"}],"wp:attachment":[{"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/media?parent=872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/categories?post=872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/seismicconsolidation.com\/wp-json\/wp\/v2\/tags?post=872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}