{"id":126,"date":"2021-05-24T18:37:28","date_gmt":"2021-05-24T18:37:28","guid":{"rendered":"https:\/\/adhc.lib.ua.edu\/ce340\/?page_id=126"},"modified":"2021-06-22T14:16:20","modified_gmt":"2021-06-22T14:16:20","slug":"lab-6-sand-cone","status":"publish","type":"page","link":"https:\/\/adhc.lib.ua.edu\/ce340\/?page_id=126","title":{"rendered":"Lab 6: Sand Cone"},"content":{"rendered":"\n<figure class=\"wp-block-embed is-type-video is-provider-vimeo wp-block-embed-vimeo wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<div class=\"jetpack-video-wrapper\"><iframe loading=\"lazy\" title=\"Sand Cone Laboratory\" src=\"https:\/\/player.vimeo.com\/video\/554404182?dnt=1&amp;app_id=122963\" width=\"640\" height=\"360\" frameborder=\"0\" allow=\"autoplay; fullscreen; picture-in-picture; clipboard-write\"><\/iframe><\/div>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Abstract<\/h2>\n\n\n\n<p>The evaluation of compaction in the field is a critical component to many construction processes. There are numerous technologies available to assess the in-situ<span id='easy-footnote-1-126' class='easy-footnote-margin-adjust'><\/span><span class='easy-footnote'><a href='https:\/\/adhc.lib.ua.edu\/ce340\/?page_id=126#easy-footnote-bottom-1-126' title='This means &amp;#8220;in place&amp;#8221; or at the original location, that is, not bringing it back to the lab.'><sup>1<\/sup><\/a><\/span> density of soils including, but not limited to sand cone, balloon, nuclear density gauge, and others. Out of these, the sand cone is the simplest, and perhaps oldest, test method. All that is required is for a hole to be dug on the jobsite. This hole is then filled with sand of known density. By measuring the weight of sand required to fill the hole, the volume can be easily calculate using the sand density. Coupled with the known weight of soil that was removed from the hole at the time of digging, the density of the in-situ soil can be calculated.<\/p>\n\n\n\n<div class=\"wp-block-group has-background\" style=\"background-color:#e5e5e5\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<p class=\"has-text-align-center\"><strong>Required Standards<\/strong><\/p>\n\n\n\n<p>The following specifications are required to complete this laboratory exercise:<br><br><strong>ASTM D1556<\/strong> &#8211; Standard Test Method for Density and Unit Weight of Soil in Place by Sand-Cone Method<\/p>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction<\/h2>\n\n\n\n<p>The sand cone test has been around for over 60 years. It is a reliable and straightforward method to measure unit weight in the field. This is an in-situ test method. While not a common test nowadays, as there are faster test methods available to determine the unit weight of a soil in the field, the sand cone remains a practical method that has no moving parts, batteries, or radioactive sources to maintain. Additionally, it is easy to see visually what is being measured.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Objectives<\/h3>\n\n\n\n<p>At the completion of this lab exercise, you will have satisfied the following objectives:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>Perform a calibration procedure for the sand cone equipment<\/li><li>Perform a field unit weight measurement using the sand cone method<\/li><li>Perform calculations necessary to determine the field unit weight<\/li><\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Learning Outcomes<\/h3>\n\n\n\n<p>At the completion of this lab exercise, you should be able to:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>understand an ASTM calibration process<\/li><li>perform calculations necessary to determine the field unit weight from sand cone data<\/li><li>understand the concept of compaction percentage<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Procedure<\/h2>\n\n\n\n<p>The sand cone test procedure is divided into four parts: calibration, preparation, execution, and analysis. ASTM D1556 will be used for the calibration and procedure methods. Up to this point, we have largely ignored the calibration procedures in ASTM standards for our test methods. However, in the case of the sand cone test, it is extremely important and is done more often than with other testing procedures. The calibration will take place in the laboratory while the actual measurement will be conducted in the field.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Calibration<\/h3>\n\n\n\n<p>There are two steps to the calibration process but you will only be conducting the first step. The second step is described in ASTM D1556 Section A.2 and determines the unit weight of the sand used for the sand cone. This unit weight will be provided to you. You will generally follow the steps outlined in ASTM D1556 Section A.1. There are two methods listed but they are nearly identical. The second method simply outlines a procedure for multiple sand cone sets.<\/p>\n\n\n\n<p>Following the procedures outlined for Method A in ASTM D1556 Section A1.2.3, you will set the base plate on the laboratory table and then weigh the sand cone apparatus. Then, place the sand cone in the base plate and open the valve and allow sand to fill the cone portion and the gap between the cone and table. After the sand stops flowing, you will close the valve and slowly remove the cone. You will then weigh the sand cone apparatus (which now has less sand in it). Finally, you will carefully scoop\/sweep the sand into a container for reuse<span id='easy-footnote-2-126' class='easy-footnote-margin-adjust'><\/span><span class='easy-footnote'><a href='https:\/\/adhc.lib.ua.edu\/ce340\/?page_id=126#easy-footnote-bottom-2-126' title='ASTM D1556 generally discourages reuse of the sand but we will be careful not to contaminate it.'><sup>2<\/sup><\/a><\/span>. Using the provided unit weight of the sand, you can easily calculate the volume of the cone and gap by using the difference in weights. This value will be your cone correction factor.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Preparation<\/h3>\n\n\n\n<p>You will need five pieces of equipment for this procedure: sand cone apparatus (Fig. 1), base plate, scoop, sample container, and a scale<span id='easy-footnote-3-126' class='easy-footnote-margin-adjust'><\/span><span class='easy-footnote'><a href='https:\/\/adhc.lib.ua.edu\/ce340\/?page_id=126#easy-footnote-bottom-3-126' title='We will not bring this into the field; we will bring the soil sample back to the lab to weigh.'><sup>3<\/sup><\/a><\/span>. Ensure the sand cone apparatus is filled with enough sand and obtain the filled weight of the apparatus. Finally, obtain the empty weight of the sample container.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"684\" src=\"https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760-1024x684.jpg\" alt=\"\" class=\"wp-image-127\" srcset=\"https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760-1024x684.jpg 1024w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760-300x200.jpg 300w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760-768x513.jpg 768w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760-1536x1025.jpg 1536w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/GEO_5760.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>Fig. 1: Assembled sand cone apparatus sitting on a base plate.<\/figcaption><\/figure>\n\n\n\n<p class=\"has-background\" style=\"background-color:#cfecff\"><strong>Checklist<\/strong><br>\u2610 Obtain sand cone apparatus and base plate<br>\u2610 Obtain scoop and sample container<br>\u2610 Obtain the filled weight of the apparatus<br>\u2610 Obtain the empty weight of the sample container<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Execution<\/h3>\n\n\n\n<p>he execution process is straightforward. You will go to the designated site and set your base plate down. Hammer the soil stakes in to stabilize the base plate while you excavate the soil with the scoop. It is critical that as you scoop soil out to form a hole that you do not lose any soil. All of the excavated soil should be placed in the sample container and sealed until you can obtain the in-situ mass back in the lab.<\/p>\n\n\n\n<p>The minimum size of the hole is listed in ASTM D1556 Section 7.1.5 and is dependent on the gradation of the soil you are testing. Essentially, we want a hole big enough to reduce error but smaller than the volume of sand in our sand cone. The shape of the hole you dig is also important as we need the sand to freely flow and fill in the hole. We cannot have overhangs or crevices that the sand would not easily reach (Fig. 2).<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"556\" src=\"https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-1024x556.png\" alt=\"\" class=\"wp-image-128\" srcset=\"https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-1024x556.png 1024w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-300x163.png 300w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-768x417.png 768w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-1536x834.png 1536w, https:\/\/adhc.lib.ua.edu\/ce340\/wp-content\/uploads\/2021\/05\/hole_cross_section-2048x1112.png 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>Fig. 2: Example hole cross sections with (A) and (B) indicating good holes and (C) and (D) indicating poor holes.<\/figcaption><\/figure>\n\n\n\n<p>After you have collected all of the loose soil in the sample container, seal it to prevent moisture loss while you complete the sand cone test. Place the sand cone apparatus on top of the base plate and ensure it is fully seated. Open the valve and allow the sand to fill the entire volume. Once the sand has stopped flowing, close the valve and slowly remove the sand cone apparatus. As previously mentioned, we generally cannot reuse the sand because it becomes contaminated with the soil we are testing on. Thus, you will leave the sand in the hole and remove the stakes and base plate for transport back to the lab.<\/p>\n\n\n\n<p>Once back in the lab, obtain the weights of the soil sample and the emptied sand cone apparatus. Your soil sample will be oven dried and the resulting oven dry mass will be provided to you. Ensure your sample container is sufficiently labeled for later identification.<\/p>\n\n\n\n<p class=\"has-background\" style=\"background-color:#cfecff\"><strong>Checklist<\/strong><br>\u2610 Excavate a hole and collect all soil in a sealed container<br>\u2610 Weigh sample container with moist soil sample<br>\u2610 Weigh emptied sand cone apparatus<br>\u2610 Place sample container in drying oven<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Analysis<\/h3>\n\n\n\n<p>The calculations for determining the densities is straightforward and clearly outlined in ASTM D1556 Section 8. We first calculate the volume of the hole. This is done by taking the difference of the starting weight and ending weight of the sand cone apparatus, subtracting the calibration value determined earlier, and then dividing by the unit weight of the sand. Keep track of your units!<\/p>\n\n\n\n<p>After the volume is known, the calculation of both wet and dry densities is easily performed. It is simply the measured wet or dry weight of the soil removed from the hole divided by the volume of the hole. The number of decimal places we can report to is outlined in ASTM D1556 Section 9.4.<\/p>\n\n\n\n<p>The last thing we need to do with our data is to see at what &#8220;percent compaction&#8221; we were at in the field. When we run a density check in the field, we are trying to see if we have reached some target compaction. It is most commonly reported as a percentage of the maximum dry density, which was determined in the lab from the standard Proctor test following ASTM D698.<\/p>\n\n\n\n<div class=\"wp-block-group has-background\" style=\"background-color:#fffad1\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<p class=\"has-text-align-center has-medium-font-size\"><strong>Example<\/strong><\/p>\n\n\n\n<p>For example, let&#8217;s assume our specimen has a maximum dry density, determined from the standard Proctor, of 125 lbs\/ft\\(^3\\). If the results of our sand cone test determine that the in-situ dry density is 121 lbs\/ft\\(^3\\), we have obtained 96.8% compaction. The required percentage depends on the project details, but minimum compaction values of 90% or 95% are most common.<\/p>\n<\/div><\/div>\n\n\n\n<p class=\"has-background\" style=\"background-color:#cfecff\"><strong>Checklist<\/strong><br>\u2610 Calculate the volume of the hole<br>\u2610 Measure dry mass of soil removed<br>\u2610 Calculate in-situ wet density<br>\u2610 Calculate in-situ dry density<br>\u2610 Calculate in-situ percent compaction<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<p>You have successfully run a sand cone test. As you likely noticed, the process is relatively straightforward and easy to run. This test used to be a routine test but was surpassed by faster and more accurate methods such as nuclear density gauges. Even though not as common, the sand cone method provides a good opportunity to visually observe how the compaction can be measured and more importantly, the size of the measurement.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Abstract The evaluation of compaction in the field is a critical component to many construction processes. There are numerous technologies available to assess the in-situ density of soils including, but not limited to sand cone, balloon, nuclear density gauge, and others. Out of these, the sand cone is the simplest, and perhaps oldest, test method. [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":19,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-126","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/pages\/126","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=126"}],"version-history":[{"count":5,"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/pages\/126\/revisions"}],"predecessor-version":[{"id":180,"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/pages\/126\/revisions\/180"}],"up":[{"embeddable":true,"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=\/wp\/v2\/pages\/19"}],"wp:attachment":[{"href":"https:\/\/adhc.lib.ua.edu\/ce340\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}