The elastic modulus increases as the quartz content increases due to the friction among the very heterogeneous quartz minerals (fine to coarse sand in size). Each of 1% increase in quartz content is followed by 5% increase in modulus of elasticity in axial condition, 2.4% increase in modulus of elasticity in diametral condition, and 0.84% increase in Poisson’s ratio.
The result shows that quartz content has a very strong correlation with modulus of elasticity in both axial and diametral conditions as well as with Poisson’s ratio, indicated by the correlation degree of above 0.90. To identify the relationship between the quartz content and the modulus of elasticity as well as Poisson’s ratio, simple regression method was implemented. Uniaxial test was performed on the samples by referring to the ASTM standard. The analysis was carried out on undisturbed samples of quartz sandstone taken from the Warukin Formation. This study aims to determine the influence of quartz mineral content in sandstone on the modulus of elasticity and Poisson’s ratio. The existence of clay-sized sand will certainly have a different impact from the clay-sized material composed of clay minerals. Sandstones are composed of clay-sized to coarse sand-sized quartz minerals, which will affect rock plasticity. High content of quartz in various sizes can affect the physical and mechanical properties, in particular the modulus of elasticity and Poisson’s ratio.
Our studies provide valuable insight in structure‐property linkages and enable a better prediction of fracture‐sealing. Additionally, we perform probabilistic simulations which show how many single‐seal microveins form side‐by‐side with a few multi‐crack‐seal veins. This implies that the degree of sealing is the cause of this division, where crack‐seal veins are microporous sites of mechanical weakness. In contrast, an incomplete sealing makes the vein weaker than the host rock and leads to a new cracking inside the vein, which enlarges the existing structure with each cycle.
#SATISFACTORY QUARTZ CRACK#
Our results show that if a fracture completely seals a new crack will form in the host rock and many thin microveins form. The basic steps of a crack‐seal process and how fracturing and sealing interact are explored. In this work we simulate the processes of fracturing and crystal growth on grain scale in a microporous rock structure and show how different crystal structures form. This affects the transport and mechanical properties of the rock system and in turn has consequences for example, in subsurface engineering applications. Fluids in the Earth's crust can alter permeability and porosity, precipitate and dissolve minerals, transport material and interact with deformation.