Soaking Effects on Strength Characteristics of Crushed Gravel and Limestone Unbound Aggregates

2018 ◽  
Vol 2672 (52) ◽  
pp. 34-45 ◽  
Author(s):  
Abdolreza Osouli ◽  
Goran Othmanawny ◽  
Erol Tutumluer ◽  
Sheila Beshears ◽  
Heather Shoup
Keyword(s):  
Quality Control ◽  
Strength Characteristics ◽  
Base Thickness ◽  
Fines Content ◽  
Limestone Aggregate ◽  
Unbound Aggregates ◽  
Transportation Agencies ◽  
Crushed Limestone ◽  
Unbound Aggregate ◽  
Aggregate Strength

Strength characteristics of unbound aggregate materials critically affect base and sub-base thickness designs of construction working platforms and flexible pavements. Unsoaked California Bearing Ratio (CBR) is commonly used by state transportation agencies for quality control and design. However, depending on the amount of fines content (i.e., passing No. 200 sieve), the strength characteristics of unbound aggregate layers may severely be affected after soaking. This study investigates any correlations that may exist between soaked and unsoaked strengths of crushed gravel and limestone aggregates commonly used in the State of Illinois. A test matrix was established to consider the effects of varying fines content at 5% and 12%, plasticity index (PI) at 5% and 9%, and dust ratio (DR) at 0.4, 0.6, and 1.0 on aggregate strength. DR is the ratio of percent passing No. 200 sieve to percent passing No. 40 sieve. Most of the aggregate strength characterizations with 5% fines content were not sensitive to soaking in terms of CBR index. However, significant reductions in soaked and unsoaked CBR values were observed when fines content increased from 5% to 12%. The crushed limestone aggregate strengths were more affected by soaking than the crushed gravel aggregates. A prediction model was developed to predict soaked CBR values from unsoaked CBR tests considering material type, fines content, PI and DR.

Comparison of properties of steel slag and crushed limestone aggregate concretes

2003 ◽  
Vol 17 (2) ◽  
pp. 105-112 ◽  
Author(s):  
M Maslehuddin ◽  
Alfarabi M Sharif ◽  
M Shameem ◽  
M Ibrahim ◽  
M.S Barry
Keyword(s):  
Steel Slag ◽  
Limestone Aggregate ◽  
Crushed Limestone

Construction Quality Control of Unbound Base Course using Light Weight Deflectometer where Reclaimed Asphalt Pavement Aggregate is Used as an Example

2020 ◽  
Vol 2674 (10) ◽  
pp. 989-1002
Author(s):  
Emre Akmaz ◽  
Saad Ullah ◽  
Burak F. Tanyu ◽  
Erol F. Guler
Keyword(s):  
Quality Control ◽  
Asphalt Pavement ◽  
Field Measurements ◽  
Design Criteria ◽  
Reclaimed Asphalt Pavement ◽  
Light Weight ◽  
Reclaimed Asphalt ◽  
Light Weight Deflectometer ◽  
Base Course ◽  
Unbound Aggregate

Reclaimed asphalt pavement (RAP) is already being recycled as a construction and building material. One of the commonly considered applications is to create an unbound aggregate from this material. However, since the particles of RAP have binder coatings, traditional quality control procedures applied during construction such as use of a nuclear density gauge does not provide accurate results. Therefore there is a need to find another method that can be applied during construction to confirm that the placement in the field meets the design criteria. For this reason, in this study, the suitability of using light weight deflectometer (LWD) has been investigated. The presented methodology outlines how to implement the use of LWD to create a target modulus in the laboratory as part of design criteria and compare with the field measurements. In the field, depending on the thickness of the constructed aggregate layer, the LWD measurements may be influenced by more than just the layer of interest. The presented methodology also provides a solution for such multilayer conditions. Although the study primarily focuses on using RAP as the investigated material, the methodology developed in this study can be applied to any type of unbound aggregate as demonstrated in this study.

Effect of fines content on frost heave

1996 ◽  
Vol 33 (4) ◽  
pp. 678-680 ◽  
Author(s):  
Robert E Tester ◽  
Paul N Gaskin
Keyword(s):  
Key Words ◽  
Frost Heave ◽  
Cold Regions ◽  
Fines Content ◽  
Frost Action ◽  
Road Base ◽  
Pavement Structures ◽  
Freezing Test ◽  
Crushed Limestone ◽  
The U.S

In regions of seasonal frost the integrity of pavement structures is dependent on the resistance of base and subbase soils to frost action. This note describes the results of performing the U.S. Army Cold Regions Research and Engineering Laboratory CRREL II laboratory freezing test on a crushed limestone with a varying fines content. Frost heave increased linearly as fines content increased. Under the CRREL frost susceptibility criterion, the crushed gravel was satisfactory with up to 8% fines. A greater fines content resulted in an unsatisfactory classification. Key words: frost susceptibility, fines content, road base.

scholarly journals Resistencia de concreto con agregado de alta absorción y baja relación a/c

2012 ◽  
Vol 2 (1) ◽  
pp. 21-28
Author(s):  
R. G. Solís ◽  
E. Moreno ◽  
E. Arjona
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Site ◽  
Cement Ratio ◽  
Limestone Aggregate ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Maximum Compressive Strength ◽  
Crushed Limestone ◽  
High Absorption

RESUMENLa resistencia del concreto depende de la calidad de la pasta de cemento y de las características de los agregados pétreos. La primera es controlada por la relación agua - cemento, mientras que las propiedades de los agregados generalmente no pueden ser manipuladas ya que se suele utilizar aquellos que están disponibles cerca de la construcción. En muchas regiones rocas con propiedades no deseables son utilizadas como agregado. Por lo tanto, el objetivo de este trabajo fue responder a la pregunta sobre cuál sería la máxima resistencia de diseño que se podría utilizar para concretos fabricados con un tipo específico de agregados obtenidos a partir de la trituración de roca caliza de alta absorción. Se probaron concretos con seis relaciones agua - cemento y dos tamaños de agregado grueso. Se concluyó que con los agregados estudiados es posible fabricar concretos de hasta 500 k/cm2 de f’c.Palabras clave: Absorción; agregados calizos; concreto; relación agua/cemento; resistencia.ABSTRACTConcrete strength depends on the cement paste quality and on the characteristics of the aggregates. The former is controlled by the water to cement ratio, while the properties of the aggregate, in general, cannot be manipulated as it is customary to employ the ones available near the construction site. In many regions rocks with no desirable properties are employed as aggregates. Therefore, the aim of this study was to answer the question about what would that be the maximum compressive strength attainable in concrete made with a specific type of aggregate obtained from crushed limestone of high absorption. Concrete mixtures involved six water to cement ratios and two sizes of coarse aggregate. It was concluded that with this type of aggregate it is possible to made concrete with compressive strength up to 500 k/cm2 of f’c.Key words: Absorption; compressive strength; concrete; limestone aggregate; water/cement ratio.

Evaluation and Quality Control of Dry-Jet-Mixed Clay Soil-Cement Columns by Standard Penetration Test

2003 ◽  
Vol 1849 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Songyu Liu ◽  
Roman D. Hryciw
Keyword(s):  
Quality Control ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Clay Soil ◽  
Soft Soil ◽  
Standard Penetration Test ◽  
Strength Characteristics ◽  
Penetration Test ◽  
Jet Mixing ◽  
Soil Cement

Dry jet mixing has been widely used since the 1980s for stabilization of soft soil. The quality and strength of the dry-jet-mixed columns must be evaluated to confirm the success of the stabilization. The standard penetration test (SPT) is shown to be a simple and effective method for this task. The strength characteristics along the length of the column were determined, and correlations between the SPT blow count and the unconfined compressive strength were developed.

Results of Soaked and Unsoaked California Bearing Rate Tests on Unbound Aggregates with Varying Amounts of Fines and Dust Ratios

2017 ◽  
Vol 2655 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Abdolreza Osouli ◽  
Sajjad Salam ◽  
Goran Othmanawny ◽  
Erol Tutumluer ◽  
Sheila Beshears ◽  
...  
Keyword(s):  
Detailed Comparison ◽  
Coarse Grained ◽  
Fines Content ◽  
Cbr Test ◽  
The Matrix ◽  
Negative Effect ◽  
Sand And Gravel ◽  
Aggregate Base ◽  
Mineral Fillers ◽  
Unbound Aggregate

Unbound aggregate base and subbase courses consist of coarse-grained materials with limited percentages of fines (i.e., passing the No. 200 sieve) allowed. The fines are mineral fillers that occupy the void spaces between the sand and gravel-sized particles. An excessive quantity of fines can negatively affect the strength characteristics of unbound aggregate layers, and this effect can easily be aggravated when the matrix is saturated. A set of unsoaked and soaked California bearing ratio (CBR) tests were performed on engineered gradations of unbound aggregate samples so that the effect of soaking on CBR test results could be studied. A detailed comparison between soaked and unsoaked CBR results was carried out by considering various index properties, such as the fines content, plasticity index, and dust ratio (percentage passing the No. 200 sieve divided by the percentage passing the No. 40 sieve). It was found that higher plasticity indexes, such as 9% and 13%, have a negative effect on both soaked and unsoaked CBR values for samples with a dust ratio of 1.0. Samples with a dust ratio of 0.4 were, in general, not influenced by soaking in terms of the CBR index. Moreover, the effect of soaking on strength reduction was noticeable when the fines content was as high as 12% and the dust ratio was greater than 0.6. Furthermore, a correlation between soaked and unsoaked CBR is also proposed on the basis of experimental results obtained from this study.

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