**2. Material properties used for compressive strength investigation**

To elaborately indicate compressive behavior of the concrete, the results for three different temperatures of 5, 10, and 25°C as well as two humidity rate index values are represented. Four cement types with low and high water-cement ratio are taken into account to understand the compressive behavior of the concrete in various environmental effects. The commercially available grout types of BASF, Dayton, Five Star, and Quickrete are prepared and cured with water-cement ratios of 0.12, 0.12, 0.18, and 0.18, respectively. The values of consistency, an indicator of the mobility or fluidity of the mortar, were checked to be in conformity with the limits set in ASTM standards. **Table 1** shows a detailed plan of testing plan with the number of samples. The mentioned mortar compositions are selected based on the applicability of them for harsh environmental condition in North USA.


#### **Table 1.**

*Testing plane for evaluating the effect of temperature and humidity index.*

All the samples were prepared in molds accordingly and consolidated with tamping rods. Roding is done for each layer uniformly on the cross-sectional area with rounded end. The number of strokes varies depending on the type of molds used, which is based on ASTM standards [14]. The samples are subsequently covered with burlaps to effectively initiate the hydration process for 24 h. Subsequently, the samples are demolded after being cured for 24 h, and the compressive strength is monitored for 1, 3, 7, 14, and 28 days curing time based on the ASTM recommended procedure [14–16]. It is noted that the mixing procedure is based on the ASTM manuals [14–16] for simulating the actual behavior of the concrete under cold, mild, and moderate temperature conditions.

It is noted that samples are remained in temperatures shown in **Table 1** for a week and then moved to room temperature area with the same humidity afterward. In general, for each grout type at each time interval, three cubic and two cylinders as well as two large rectangular samples for freeze-thaw durability index test are made for compressive strength development investigations.
