Methods, systems, and computer program products for determining a property of construction material

#The subject matter described herein relates to measuring material properties. More particularly, the subject matter described herein relates to methods, systems, and computer program products for determining property of construction material.

#An important aspect of construction engineering is road construction and maintenance. The ability to design and construct roads based on future loads and environmental factors is very important as it saves time, effort, and resources in future maintenance costs. A well-designed road will have long-term performance when the design factors of loading, climatic, and soil conditions are accounted for properly.

#In construction engineering, some of the most important properties of interest are volumetric and mechanistic properties of construction materials such as soil, asphalt, concrete, and the like. In particular, there are procedures in construction engineering practice that relate total volume Vt, mass of water Mw, and mass of dry solids MS to the performance of a structure built on a soils foundation. Other important properties of interest are mechanical properties such as stiffness, modulus, and density. Thus, the measurements of these properties are important for construction engineering.

#Preferred embodiments of the subject matter described herein will now be explained with reference to the accompanying drawings of which:

#FIG. 1A is a vertical cross-sectional view of a material property gauge for measuring the density or modulus of material according to an embodiment of the subject matter described herein;

#FIG. 1B is a schematic diagram illustrating a use of an exemplary acoustic source and an exemplary acoustic detector for determining a density and modulus of a sample material;

#The subject matter described herein includes methods, systems, and computer program products for determining a property of construction material and/or various other materials. In one embodiment, the methods, systems, and computer program products described herein may determine a property value associated with a construction material under test. Exemplary construction materials include asphalt, soil, concrete, aggregate, and the like. Exemplary property values that may be determined include moisture content, Poisson ratio, modulus, shear strength, density, void content, and the like. According to one aspect, a material property gauge may include an electromagnetic sensor operable to measure a response of construction material to an electromagnetic field. The electromagnetic sensor may produce a signal representing the measured response by the construction material to the electromagnetic field. An acoustic detector may detect a response of the construction material to acoustical energy. Further, the acoustic detector may produce a signal representing the detected response by the construction material to the acoustical energy. A material property calculation function configured to calculate a property value associated with the construction material based upon the signals produced by the electromagnetic sensor and the acoustic detector. In one example, a material property calculation function may use a moisture content measurement for correcting determined property values of construction material.

#Another important factor affecting the modulus of construction material includes temperature, particularly with asphalt. In another embodiment of the subject matter described herein, material property gauges and related methods are provided for using temperature measurements in material property calculations, particularly for making corrections to determined property values of construction material. According to one aspect, a material property gauge may include an electromagnetic sensor operable to measure a response of construction material to an electromagnetic field. The electromagnetic sensor may produce a signal representing the measured response by the construction material to the electromagnetic field. A temperature detector may correct a response of the construction material to acoustical or electromagnetic energy. A material property calculation function configured to calculate a property value associated with the construction material based upon the signals produced by the electromagnetic sensor and the temperature detector.

#In one example of a property of interest in road construction engineering, mechanistic design methods characterize pavement based on its elastic response to a vehicular load. In this example, the pavement structure may be composed of asphaltic material or concrete surface, base, and subgrade, each having a material thickness t and characterized by the elastic modulus E, Poisson ratio v, and aggregate interface friction f. This results in a layered elastic system that can be analyzed using engineering mechanics. As a result, design and performance can be estimated from computations or measured stress and strains on each layer resulting in a systematic design and predicted response from the surface.