This study examines the mineralogy, texture, and weathering grades of intrusive igneous rocks from northern Pakistan, as well as their impacts on physical and strength properties. In comparison to felsic rocks, mafic and intermediate rocks have lower cumulative proportions of quartz, feldspar, and plagioclase, as well as higher specific gravity, strength (i.e., UCS and R-value), and UPV values. Similarly, samples with anhedral grain shapes, irregular boundaries, and fine to medium grain sizes (UD, ANS, and CGN) exhibited greater strength values, with compressive strengths of 121, 118, and 91 MPa and tensile strengths of 11, 9, and 12 MPa, respectively. The physical and strength properties of the investigated samples corresponded well with the weathering grades assigned to them, such as fresh (WG-I), slightly weathered (WG-II), and highly weathered (WG-III). That is, as the grade increased from WG-I to WG-III, the porosity and water absorption increased (0.28% and 0.72%, respectively), whereas the specific gravity, compressive strength, and tensile strength decreased (2.04, 20, and 2.5 MPa, respectively, for CGA). Although the presence of quartz impacts rock strength, no significant association was found between the strength and the maximum and mean grain sizes of other minerals.

Long tunnels with significant overburden, changeable geological conditions, a steep gradient, water infiltration, and heavy traffic flow are susceptible to environmental concerns during both construction and operation. The availability of fresh air and visibility is the most important necessity in excavation for tunnel workers inside the tunnel during the construction phase, as well as those crossing the tunnel during operation. Lowari Tunnel’s tunnel air pollutants were researched. Carbon monoxide (CO), carbon dioxide (CO₂), oxygen (O₂), hydrogen sulfide (H₂S), sulfur dioxide (SO₂), nitrogen oxide (NO), ammonia (NH₃), nitrogen dioxide (NO₂), PM₁, PM_2.5, PM₁₀, air velocity, dust morphological and particle size distribution analysis are among the parameters under consideration. The findings provide evidence for the development of tunnel air quality.

The utilization of dimension stone in construction has been prevalent since ancient times; however, its application in modern construction has gained significant attention over the last few decades. This research aimed to assess the physical and strength properties of volcanic rocks from the Kohistan Island Arc for their potential use as dimension stone. Five types of andesites (MMA, PMA-1, PMA-2, CMA, and FMA) and two types of agglomerates (AG-1 and AG-2) were identified based on their composition, color, and texture. The samples were characterized in terms of their petrography (compositional and textural), physical properties (specific gravity, water absorption, and porosity), and strength properties (unconfined compressive strength and unconfined tensile strength). Two non-destructive tests (ultrasonic pulse velocity test and Schmidt hammer) were conducted, and the degree of polishing was evaluated. Correlation analyses were carried out to establish possible relationships among these parameters. The presence of chlorite, epidote, sericite, and recrystallized quartz indicated signs of low-grade metamorphism in andesites. The study revealed that feldspar, amphibole, and quartz imparted good physical and strength properties to samples MMA, CMA, FMA, AG1, and AG2. On the other hand, PMA-1 and PMA-2 exhibited reduced physical and strength properties due to the abundance of alteration products like chlorite, sericite, and epidote. The unconfined compressive strength exhibited a strong correlation with ultrasonic pulse velocity, skeletal density, porosity, and water absorption. Weathering grade considerably affected the values of ultrasonic pulse velocity and Schmidt hammer. Consequently, samples PMA-1 and PMA-2 are not recommended for load-bearing masonry units and outdoor applications due to their high water absorption and low strength values. On the other hand, samples FMA and MMA exhibited excellent properties like high strength and good polishing, indicating their potential use as decorative and facing stones, external pavement, ashlar, rubbles, and load-bearing masonry units.