LAYOUT OF CONSTRUCTED TEST SECTIONS

The construction took place at the Illinois Center for Transportation’s (ICT) accelerated pavement testing facility. The Google satellite image of the construction site, showing the plan view of the constructed pavements is shown in Figure 4.1. A detailed plan view of the test sections is also given in Figure 4.2 of this report. In total, 16 test sections were constructed. The constructed roads were divided into four test blocks (Cells) designated by: Cell 1 (Cell 1S, and Cell 1N), Cell 2, and Cell 3. Each Cell marks one testing location with ATLAS, and is further subdivided into four test sections, each studying a different QB application.

Figure 4.1. Google satellite view of the construction site showing overall the constructed test cells.

Cell ‘1’ (Figure 4.2 and Table 4.1) was constructed 119 ft. (35.6 m) long and 18 ft. (5.4 m) wide. Four test sections, each approximately 20 ft. (6.1 m) long and wide 9 ft. (2.7 m) were constructed to study the ‘subgrade modification’ applications of QB; namely, PCR/QB1 mixed by shaking and compacting the QB on top of large rocks in a single lift and in two lifts, and the dense-graded aggregate subgrade layers with 15% plastic and nonplastic fines passing the No. 200 sieve. For each section, a 21-in. (530- mm) thick aggregate cover and a 3-in. (76-mm) of dense-graded CA06_R capping material were constructed. The 9-ft. (2.7-m) wide north test sections were topped with an additional 4-in. (100-mm)

thick HMA layer to evaluate low volume road applications, and are denoted as Cell ‘1N’. The 9-ft. (2.7-m) south test sections were built to evaluate construction platform applications and was called Cell ‘1S’. Cell 1 was constructed on top of a subgrade soil with an engineered CBR of 1%.

Table 4.1. Constructed Test Sections for Cell 1 Utilizing Unstabilized Applications of QB Section Description and Construction Details* Typical Cross Sections C1S1

Primary Crusher Run (PCR) rocks with 25% QB1 by weight, constructed in two equal lifts using a

vibratory roller compactor. QB1 is placed into the voids of the PCR from the top of each lift.

Cell 1S

Cell 1N C1S2 PCR with 16.7% QB1 by weight, constructed in

one single lift in a similar manner as C1S1. C1S3

CA06_15PF: Dense-graded CA06 aggregates with 15% plastic fines content (passing No. 200 sieve) with a plasticity index (PI) of 8

constructed in three equal lifts.

C1S4 CA06_15NPF: Dense-graded CA06 aggregates _{with 15% nonplastic fines content (passing No.}

200 sieve) constructed in three equal lifts.

* All test sections in Cell 1 were overlain by a 3-in. (76-mm) thick dolomite capping (CA06_R material). For Cell 1N, a 4 in. (100-mm) thick HMA layer was paved on top of the capping layer.

Cell ‘2’ (Figure 4.2 and Table 4.2) was constructed 119 ft. (35.6 m) long and 12 ft. (3.6 m) wide. Four

test sections, each approximately 20 ft. (6.1 m) long, were constructed to study the ‘base’

applications of QB; namely, [70% QB2 + 30% FRAP] + 3% Cement of the total weight, [70% QB2 + 30% FRCA] + 3% Cement base, [70% QB2 + 30% FRAP] + 10% Fly ash, and [100% QB2] + 3% Cement base. The base layers were 12 in. (305 mm) thick and were topped with 4-in. (100-mm) of HMA to evaluate low to medium volume road applications. Cell 2 was constructed on top of a subgrade soil with an engineered CBR of 6%.

Cell ‘3’ (Figure 4.2 and Table 4.2) was constructed 130 ft. (39.0 m) long and 12 ft. (3.6 m) wide. Four test sections, each approximately 20 ft. (6.1 m) long, were constructed to study the base and subbase applications of QB. The first test section was constructed with [100% QB3 + 3% Cement] base, to evaluate the effect of the QB type (QB2 vs QB3 differences). Two of the sections evaluated inverted pavement applications of QB, and were constructed with a 6-in. (152-mm) thick QB2 subbase layer stabilized with 3% cement and 10% fly ash respectively, and topped with 6-in. (152-mm) of dense- graded CA06_R aggregate base. The last section was a control section, constructed with 12 in. (305

mm) of regular dense-graded base course material. All four sections were overlain by 4 in. (100 mm) of HMA to evaluate low to medium volume roads applications. Cell 3 was constructed on top of a subgrade soil with an engineered CBR of 6%.

Table 4.2. Constructed Test Sections for Cells 2 and 3 with Admixture Stabilized Applications of QB Section Description and Construction _Details* Typical Cross Sections

C2S1 A blend of 70% QB2 and 30% FRAP by weight, mixed with 3% Type I cement by weight.

Cells 2 and 3

Cell 3 (C3S2 and C3S3) C2S2 A blend of 70% QB2 and 30% FRCA by

weight, mixed with 3% Type I cement by weight.

C2S3 A blend of 70% QB2 and 30% FRAP by weight, mixed with 10% Class ‘C’ fly ash by weight.

C2S4 A Blend of QB2 and 3% Type I cement by weight.

C3S1 A Blend of QB3 and 3% Type I cement by weight.

C3S2 Subbase layer: A Blend of QB2 and 3% Type I cement by weight.

Base layer: CA06_R (A dense-graded unbound dolomite aggregate layer)

C3S3 Subbase layer: A Blend of QB2 and 10% Class ‘C’ fly ash by weight. Base layer: CA06_R

C3S4 CA06_R dense-graded dolomite base

Longitudinal and transverse drainage lines were installed to drain water efficiently from the test sections (Figure 4.2). Longitudinal drainage lines ran along the north side of each cell, and a

transverse drainage line ran from south to north along the west side of Cell 3 and connected to the longitudinal drainage line. Perforated, plastic drainage pipes were covered with an open-graded granular material that follows IDOT CA07 gradation band for grain size distribution. A storage basin and a sump pump were utilized to store and divert the water from the test sections (see Figure 4.2). Additionally, the beginning and end parts of each cell were designed to have 22.5 ft. (6.8 m) long crawler zones (where the crawlers of ATLAS were placed) and a 7.5 ft. (2.3 m) speed stabilization zone. The speed stabilization zones were for acceleration/deceleration to ensure that all test sections were tested at a constant speed of 5 mph (8 km/h). A 10 ft. (3 m) long transition zone was also added at the middle of each cell, to minimize any possible influence of changing materials on the APT

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results. Figure 4.3 shows the details of the transition and buffer zones for each cell. Further, the transverse rut profile measurement lines are also indicated in each test section at one third lengths.

Figure 4.2. Plan view of the constructed test sections encompassing different QB applications.

Figure 4.3. Plan view of a typical test cell showing the transition and buffer zones and the transverse measurement lines.