Implementation of a fine aggregate angularity test tim aschenbrener 1. Apparatus cylindrical measure, funnel pycnometer top, funnel stand, square glass plate, pan, metal spatula, balance procedure met. Test methods for characterizing aggregate shape, texture. Exp 2 aggregate angularity number civil engineers pk. This test is used to help ensure that the resulting hma mixture will be resistant to deformation under repeated loads. Fine aggregate angularity is important because an excess of rounded fine aggregate often in the form of natural sand can lead to hma rutting. Research article effect of shape and size of aggregate on. This method of test determines the loose uncompacted void content of fine aggregate samples.
Faa measures the angularity of fine aggregate by measuring the loose uncompact void content of the fine aggregate sample. Uncompacted void content provides an indication of angularity, sphericity, and surface texture for an aggregate of known gradation. Quantify shape, angularity and surface texture of aggregates using image analysis and study their effect on performance by dallas little senior research fellow. The fine aggregate angularity tests air voids method t 03442000 were conducted on all these fine. Uncompacted void content of fine aggregate uvc astm c1252. Fine aggregate degradation index of aggregate quality. A convenient and reliable test has been developed for determining the angularity of aggregates.
Fine aggregate angularity apparatus measures uncompacted void content of fine aggregates using the astm c1252aashto t 304 method. It provides a measure of aggregate angularity, sphericity, and texture compared to other fine aggregates tested. Particle size and shapeeleventh reprints bureau of indian standard, new. Clowers the state of kansas currently requires a mm1mum percentage of. Determination of fine aggregate angularity in relation. Researchers evaluated angularity of 23 fine aggregates representing most types of paving aggregates used in the usa using seven different procedures. Based upon shape the aggregates may be classified as rounded, angular or flaky. Table 2 gives the properties including the fine aggregate angularity faa of the four fine aggregates. Dotd s 101 sampling aggregates aggregate mixtures 2. Our asphalt mix design technician is running this test to determine the angularity and loose, uncompacted void content of fine aggregates.
Evaluation of fine aggregate angularity using national. The fine aggregate angularity test determines the loose uncompacted void content of a fine aggregate material. The void content information derived from this test gives you an indication of the effect fine aggregate will have on stability and voids in the mineral aggregate. Aim the fine aggregate angularity test determines the loose uncompacted void content of a fine aggregate material. Scope this test method describes the procedure for determining the loose uncompacted void content of a sample of fine aggregate. In order to study the impact of fine aggregate angularity on the shear strength of the mix, this study selected one coarse aggregate and five different fine aggregates with the same gradation. This test is also carried out for determining shape of the aggregates. T 304 uncompacted void content of fine aggregate astm test methods d 4791 flat particles, elongated particles, or flat and elongated. Increasing fine aggregate angularity will increase the vma voids in mineral aggregate thereby reducing durability of the pavement dangelo 1996. Properties of these two coarse aggregates are provided in table 1. Stone c is granite, stone d is diabase, stone e is river sand, and the other two are limestone. The fine aggregate angularity test determines the loose uncompacted void content of a fine aggregate sample.
Coarse aggregate angularity apparatus meets aashto t 326 requirements for determining uncompacted void content of coarse aggregates for hotmix asphalt pavements. Validation of superpave fine aggregate angularity values final report prepared by. Specifying a minimum percentage of coarse aggregate angularity can also be used to obtain improved durability for aggregates used in surface treatments and to obtain increased friction and texture for aggregates used in pavement surface courses. Influence of sand angularity on standard test for strand bond. The fine aggregate angularity test faa, adopted by superpave to evaluate the shape, angularity and surface texture of fine aggregate particles, has left a lot of doubts regarding its suitability. Implementation of a fine aggregate angularity test cdot. Making a sieve analysis test of coarse aggregate in a laboratory. The void content information derived from this test. Effects of aggregate angularity on mix design characteristics and. Ministry of transportation, ontario test method ls609 rev. A study was undertaken to evaluate the ability of current superpave faa method to measure fine aggregate angularity, to determine if it can distinguish between good performing and poor performing aggregates, and compare faa test results with other measures of particle angularity. The fine aggregate angularity apparatus determines the uncompacted void content of fine aggregates to determine angularity and sphericity properties that affect workability of mix designs. Fine aggregates four fine aggregates of different mineralogical compositions, particle shape and surface texture were used in this study. The most recent accepted astm standard test for fine aggregate angularity is astm c1252, though researchers in the superior performing asphalt pavement superpave industry have questioned the accuracy of this.
Aashto test methods t 2 sampling of aggregates t 11 materials finer than 75 m no. A manual for design of hotmix asphalt with commentary incorporates the many advances in materials characterization and hotmix asphalt hma mix design technology developed since the conclusion of the strategic highway research program shrp. Pdf the performance of hotmix asphalt hma pavements depends on the properties and proportions of the major components, i. The faa test estimates fine aggregate angularity by measuring the loose uncompacted void content of a fine aggregate sample. Astmc1252 standard test methods for uncompacted void. Physical properties of aggregates rowan university. The laboratory must be aashto accredited in at least two of the three following test procedures.
Fine aggregates from different regions of usa were collected. The total blended aggregate from the fine and coarse aggregates, and recycled materials used in hma are required to meet the fine aggregate angularity faa requirements of section 904. Transportation research record 1437 43 evaluation of fine aggregate angularity using national aggregate association flow test stephen a. The fine aggregate angularity faa test figure 1 is an indirect method of. Evaluation of compacted aggregate resistant test compared with the fine aggregate angularity standards. Quantify shape, angularity and surface texture of aggregates. The national aggregate association naa has developed a new flow test appendix c to measure angularity. The important characteristics of aggregates for concrete are listed in table 52 and most are discussed in the following. Set includes strikeoff bar and glass calibration plate. Superpave testing method, aashto t304, is considered reasonable in a practical. Friction angle derived from direct shear tests and slenderness ratio from the image analysis showed good correlations with rut depth.
Fine aggregate angularity faa test is an indirect method of accessing the angularity of the fine aggregates. Also rutting test results showed that higher faa values increased resistance to rutting of hotmix asphalt. Angularity is a very important characteristic of aggregate, but no real good test had been available to measure angularity. Ls602, method of test for sieve analysis of aggregates ls616, procedure for the petrographic analysis of fine aggregate. Produced in cooperation with the upper great plains transportation institute at ndsu. Sd 217 method of test for fine aggregate angularity 1. The faa test estimates fine aggregate angularity by measuring the loose. Test methods for characterizing aggregate shape, texture, and angularity examines a methodology for classifying aggregates based on the distribution of shape, texture, and angularity characteristics. Aldot249 procedure for acceptance of fine and coarse aggregates table of contents applicable documents listing 2.
Test methods for fine aggregate angularity considering. There is also a pooled fund project 176 at purdue university to evaluate the superpave coarse and fine aggregate angularity requirements and determine their relationship to performance for refinement of the specifications. Fine aggregate angularity plastic limit surface moisture tests. When measured on any aggregate of known grading, void content provides an indication of that aggregate s angularity, sphericity, and surface texture compared to other fine. Fine aggregate angularity important because excess of rounded fine aggregate can lead to rutting. The 19 different gradation and aggregate source combinations are tested using the fine aggregate angularity test method c as outlined by aashto t304 2003. Test procedure basics standard gradation charge drum with prescribed number of steel balls and aggregate aggregate and steel balls subjected to specified number of rotations sieve all material over specified size result expressed as % changes in. When measured on any aggregate of a known grading, void content provides an indication c122 that aggregate s angularity, sphericity, and surface texture compared with other fine aggregates tested in the same grading. Aggregate fine a natural or manufactured sand having hard, clean, durable, uncoated. The shape, angularity, and texture of aggregates affect several portland cement concrete pcc properties, such as workability, water demand, and coarse aggregate.
Angular particles possess well defined edges formed at the intersection of. The procedure for determining the faa value is described in method a of aashto t 304. Trbs national cooperative highway research program nchrp report 555. Physical test procedures for measuring the consensus properties 5. When measured on any aggregate of a known grading, void content provides an indication of that aggregates angularity, sphericity, and surface texture compared with other fine aggregates tested in the same grading. Characterization of coarse aggregate angularity using. Laboratory test results for aggregates and mixtures were analyzed together using statistical. Reducing samples of fine aggregate to testing size astm c702, aashto t248 duration. One of the key components of the aggregate structure is the angularity of the fine aggregate.
Pdf determination of the angularity number of the given. Trbs national cooperative highway research program nchrp report 673. Standard test methods for uncompacted void content of fine. Part i 1963, indian standard, method of test for aggregates for concrete, part i. This test method describes the procedure for determining the loose uncompacted void content of a sample of fine aggregate. When measured on an aggregate of a known grading, void content indicates the aggregate s angularity, sphericity, and surface texture compared with other fine aggregates tested in the same grading. An examination of the existing methods indicated that the determination of the volume of voids in the aggregate when placed in a standard way was the most promising. Angularity of the fine aggregates was measured using superpave fine aggregate angularity faa, direct shear test, compacted aggregate resistance car, and vdg40 videograder. Evaluation of superpave fine aggregate angularity specification.