ConnexFrame — Composite Shear Connector System for PCSPs

01 · The Problem

A national-scale envelope inefficiency.

Why the U.S. precast wall stops performing the moment it leaves the plant.

U.S. buildings waste $150 billion in energy every year — and most of it leaks through the wall.

The opaque envelope — walls, roofs, foundations — accounts for 28% of building energy use, equivalent to 11% of total U.S. primary energy (DOE, 2023 · EIA CBECS).

In precast concrete sandwich panels (PCSPs), metallic shear ties create "thermal short circuits": discrete bridges of 2–6 °C over each anchorage, eroding up to 30% of the panel's nominal R-value (Sorensen et al., UNL 2019).

Independent guarded hot-box testing has measured R-value losses of 38–45% against the rated value for sandwich panels with conventional ties (ORNL · Kosny et al., 2006).

The industry has lived with the structural / thermal trade-off for 30+ years — high composite action or good thermal performance, never both. No ICC-ES-certified connector combines them (PCI Journal · Einea et al. 1991 · Al-Rubaye et al. 2018).

$150B

Wasted yearly in U.S. building energy

DOE, 2023

38–45%

R-value lost to thermal bridging

ORNL · Kosny et al., 2006

28%

Building energy through opaque envelope

DOE BTO · EIA CBECS

30+ yrs

Unsolved structural / thermal trade-off

PCI Journal · 1991, 2018

National Impact

A direct contribution to U.S. energy security and federal climate priorities.

ConnexFrame is engineered to advance multiple declared U.S. national interests simultaneously.

Solving the envelope-loss problem is, by direct extension, a U.S. national priority.

Reducing the documented building-envelope energy loss by even 20% would save the U.S. economy approximately $30 billion per year and avoid millions of metric tons of CO₂ emissions (derived from DOE 2023 baseline).

ConnexFrame’s multi-zone composite architecture is engineered to operationalize four declared U.S. federal mandates:

DOE Industrial Decarbonization Roadmap — high-performance envelopes named as a primary lever for cement and steel sector decarbonization.
EERE Building Energy Codes Program — state-level implementation of ASHRAE 90.1-2022 and IECC 2024 across all 50 states.
Inflation Reduction Act §13501 — Advanced Industrial Facilities credit for U.S.-deployed clean-construction technologies.
Federal Buy Clean Initiative — preference for low-embodied-carbon construction materials in federal procurement (Executive Order 14057).

The current U.S. composite-connector market is dominated by foreign-owned multinationals (CRH/Leviat is Irish-British). An independently advanced, U.S.-deployed alternative strengthens national supply-chain resilience in critical building technologies.

~$30B

Annual U.S. savings potential at 20% reduction

Derived from DOE, 2023

4

Federal programs directly aligned

DOE · EERE · IRA · Buy Clean

50

States adopting updated energy codes

DOE determination · 6 Mar 2024

U.S.

Independent challenger to foreign incumbents

CRH (IE/UK), Owens (US), Dayton (US)

02 · Context

Regulation, supply chain, capital — converging on the same year.

ASHRAE 90.1-2022 and IECC 2024 take effect across U.S. states in March 2026.

Three vectors are hitting the U.S. precast market simultaneously.

Regulation · Effective Mar 2026

ASHRAE 90.1-2022 §5.5.5

+ IECC 2024 §C402.7. Materials with conductivity ≥ 3.0 Btu·in/(h·ft²·°F) — including steel and concrete ties — must now be mitigated or accounted for through U-factor derating. DOE Federal Register determination, 6 March 2024.

Market Structure

A concentrated oligopoly

Dominated by large industrial groups: CRH/Leviat (Thermomass), Dayton Superior (HK Composites), and Owens Corning (THiN-Wall). Several also control precast plants — a vertical integration no independent challenger has entered.

Capital Flow

$46M+ in DOE programs

DOE Building Efficiency programs plus the Inflation Reduction Act (2022) — which directed roughly $369B toward energy and climate, including building efficiency — and the DOE Building Decarbonization Blueprint, which names the high-performance envelope a national priority. A strong federal tailwind for compliant connector architectures.

03 · The Solution

ConnexFrame — three-zone multi-material architecture.

One connector designed for both axes of the trade-off.

01

Structural Core

Structural Steel

Straight cylindrical core · Ø 5.0 mm · primary load path

Tensile peak 360.2 MPa, ductile rupture with necking — ICC-ES AC320 alignment.

02

Encapsulation

Pultruded GFRP

E-glass / vinyl-ester ring · Ø 4–8 mm

Triple function: electrochemical isolation, secondary composite transfer, radial thermal attenuation.

03

Helical Anchorage & Thermal Break

VE + GMB + Basalt

Proprietary 4-start helix · Ø 10–14 mm · pitch 89.4 mm

Aromatic vinyl-ester matrix with 10% hollow glass microspheres + 12% basalt fibers. Mechanical anchorage and thermal break.

Internal load path is strictly cylindrical. Only the external envelope is helical. This is the patentable distinction.

04 · Technical Differential

Functional geometric separation, by design.

Why this geometry and this composite — and not the legacy hybrid.

Why separate the functions?

Legacy hybrid connectors combine structure and anchorage in a single continuous helical body. Three documented limitations:

Helical torsion induces parasitic secondary stresses in axial load transfer.
Single complex part drives molding/machining cost up.
No independent tuning of load path vs. anchorage / thermal break.

ConnexFrame separates them. Internal zones stay strictly cylindrical (clean axial path); only the external envelope is helical (anchorage + thermal break). Each can be tuned independently to the panel geometry, the climate zone, and the structural target.

Why this composite (VE + GMB + Basalt)?

The external envelope is a hierarchical multi-scale composite. Each component does a distinct, complementary job:

Aromatic VE matrix

Alkaline-resistance (pH ≈ 13), thermal stability

10% hollow glass microspheres (GMB)

Thermal-conductivity reduction, cure stability

12% basalt fibers

Directional mechanical reinforcement, durability

Field result — absence of localized thermal gradients over anchorages. Preliminary, qualitative. Quantitative R-value confirmation under ASTM C518 in an ISO/IEC 17025 lab is planned, not yet executed.

Why the market never had to solve this. The two ICC-ES acceptance criteria for these connectors evaluate different things in isolation — AC320 covers anchorage / pull-out, AC422 covers shear / composite action. Neither criterion requires thermal-conductivity or thermal-bridging measurement. No certification has ever forced a connector to demonstrate structural and thermal performance together — precisely the gap ConnexFrame is engineered to close.

05 · Physical Proof

Prototypes fabricated. Panels cast. Equipment calibrated.

Not a concept — built, tested, and instrumented at an ISO/IEC 17025-accredited laboratory.

Family of 5 prototype connectors — **Prototype family** — V1 through V3 iterations, with a millimeter ruler for scale.

Test panel assembly with connectors embedded — **Test Panel Assembly** — Penz Engineering · concrete cast around ConnexFrame connectors prior to compression testing.

UPF/CETEC laboratory — **UPF/CETEC accredited lab** — Emic SSH300 press with acquisition station.

Sandwich panel in 2000 kN press — **PCSP specimen on the press** — 500×500×120 mm panel, Work nº 8654.

**Schenck Universal tensile rig** — German precision platform for material characterization.

DJI Matrice 4T radiometric drone — field thermography on three PCSP prototypes installed outdoors — **DJI Matrice 4T drone** — radiometric thermography on three PCSP prototypes outdoors.

Panel post-test — EPS core intact — **Post-compression panel** — EPS core preserved 100%, no delamination.

Steel core necking after tension — **Steel core after tension** — ductile rupture with visible necking.

**Thermal vs. visible** — three PCSP panels side-by-side, March 2026.

06 · Validated Data

Three parallel validation campaigns — March to May 2026.

Numbers and modes of failure that survive engineering scrutiny.

01COMPRESSIONUPF/CETEC · 28 Apr 2026

0MPamean panel resistance · CV 7.88%

CP	Area	Load	σ
CP1	65,278 mm²	47,056.68 kgf	7.07 MPa
CP2	65,792 mm²	40,630.44 kgf	6.06 MPa
CP3	60,652 mm²	39,702.53 kgf	6.42 MPa

3 CPs · 500×500×120 mm · Method BLOCO · Work nº 8654
Ductile failure in concrete face — EPS core 100% intact
Crack ~0.10 mm — within NBR 6118 / ACI 224R limits

02TENSION · STEEL COREUPF/CETEC · 06 May 2026

0MPaultimate stress σu

Schenck Universal — CF-T01/01
Section	Ø 5.0 mm · A = 19.63 mm²
L₀	100 mm
Max load	7,072.47 N
σy	347.3 MPa · σu/σy = 1.04
Elongation	24.89%
Energy absorbed	96.21 N·m

Ductile rupture with visible necking · AC320 / ASTM D7205 / D3039

03THERMOGRAPHY · QUALITATIVEField · 31 Mar 2026

Uniformno localized thermal gradients

Panel	Mean	Δmax
V1 (SP1–SP5)	27.5 °C	0.3 °C
V2 (SP6–SP9)	26.6 °C	0.1 °C
V3 (SP10–SP13)	26.6 °C	0.7 °C

DJI Matrice 4T · radiometric · ε = 0.95 · Tamb 25.9 °C
Qualitative · ASTM C518 quantitative confirmation planned

07 · Transparency

Absence of localized thermal gradients over anchorages.

Open thermography — a market-first disclosure.

A connector with active thermal bridging would show discrete hot spots or cold annular zones over each anchorage — the visual signature documented by Sorensen et al. (UNL, 2019) as 2–6 °C gradients over conventional metallic ties.

Across 13 measurement points on three PCSP prototypes — including positions directly over the anchorages and intermediate control regions — variation within each panel stayed at 0.1–0.7 °C. Distribution was dominated by ambient gradients, not by the connectors.

To our knowledge, as of May 2026, no competing connector vendor — Thermomass/Leviat, HK Composites, Owens Corning THiN-Wall, AltusGroup CarbonCast, ICONX — publishes open thermograms of their product.

ConnexFrame is, to our knowledge, the first composite shear connector to publish open field thermography of its installed system.

Preliminary and qualitative. Quantitative R-value confirmation under ASTM C518 in an ISO/IEC 17025-accredited lab is planned — not yet executed.

DJI Thermal Analysis Tool 3 — 13 points across three panels

DJI Thermal Analysis Tool 3 · 13 measurement points (SP1–SP13) on three PCSP panels · 31 March 2026.

08 · Competitive Landscape

Five incumbents, one open dataset.

Benchmarking — what each vendor publishes and what they don't.

Vendor	Product	Type	Open thermography	R-value disclosed	ICC-ES
Thermomass / LeviatCRH Group	CC, MC, MS series	FRP composite	— Not published	λ ≈ 0.46 W/m·K (datasheet)	ESR-1746 · 2873
HK CompositesDayton Superior	Composite Tie	FRP	— Not published	Not published	ESR-3201
Owens Corning	THiN-Wall System	Tilt-up sandwich	— Not published	System-level only	System-level
AltusGroup	CarbonCast	C-GRID	— Not published	Not published	ESR-2953
ICONX	Steel-tie	Metallic	— Not published	Not published	—
ConnexFramePenz Engineering	ConnexFrame V3	Multi-zone composite	✓ Open thermography	Planned ASTM C518	Pre-application

The two-product tell. The market leader holds separate ICC-ES evaluation reports for each side of the trade-off — ESR-1746 and ESR-2873 — i.e. two distinct products, one tuned for structure and one for thermal. A specifier must still choose. ConnexFrame is architected so the choice disappears.

Sources: Leviat / Thermomass commercial literature (ESR-1746, ESR-2873) · ICC-ES report directory · HK Composites datasheet (ESR-3201) · Owens Corning · AltusGroup (ESR-2953) · ICONX product pages.

09 · The Application

ConnexFrame Designer App — sizing, ROI, benchmarking.

ConnexFrame is delivered as a system, not just a part.

The ConnexFrame Designer App is a connector-sizing and decision-support tool for precast engineers. It outputs the connector count, recommended spacing, comparative cost, energy-savings estimate, and side-by-side benchmarking against the connectors actually specified in the U.S. market today.

Sizing calculator — connector count + spacing by panel geometry, insulation, climate zone
Panel-layout preview — connector distribution across the panel
Energy-savings calculator — ROI per panel by climate zone
Competitive benchmarking — NJI-Tie · ICONX · Thermomass CC · Delta-Tie
Cumulative project savings — total cost, energy, CO₂ savings vs. baseline

Methodology: benchmark connector counts sourced from Concrete Industries THiN-Wall reference panel (56"×5", April 2024) and scaled against AC422 pull-out values from each vendor's third-party validation. Field-validated values pending Phase 02 university tests.

Launch the Designer → Free · No login required · Runs in browser

ConnexFrame Designer · Connectors tab

10 · Intellectual Property

What is protected — and what isn't.

USPTO provisional filed. The claim is the combination, not the helix alone.

USPTO Provisional · 35 U.S.C. § 111(b)

Title. Multi-Zone Composite Shear Connector with Helical External Envelope in Multi-Additive Thermosetting Composite for Precast Concrete Sandwich Panels.

Inventor. Guilherme Penz · sole inventor · Micro Entity (37 CFR §1.29) · 10 drawings on 6 sheets.

Helical geometry alone is prior art

Helical anchorage in cementitious applications is prior art (e.g., Helifix-type systems). FRP composite ties in PCSPs are prior art (Thermomass, HK Composites). Neither, alone, is patentable.

What is defensibly claimed

01

Functional geometric separation between cylindrical internal load path and helical external anchorage / thermal break.

02

Multi-additive composite formulation for the external envelope: VE matrix + 10% hollow glass microspheres + 12% basalt fibers.

03

Application to PCSPs with specified geometric parametrics: Ø 10–14 mm crests, 4-start helix, 89.4 mm pitch, 60–300 mm length range.

04

Best-mode disclosure embedded — process parameters and CAD parametric model in V16 of the application.

11 · Engineering Leadership

Sole inventor, lead engineer, present at every test.

Direct laboratory presence guarantees full technical traceability, protocol adherence, and individual accountability over every result.

Compression · Apr 2026 · UPF/CETEC

Tension · May 2026

Thermography · Mar 2026

Guilherme Penz

Founder & Chief Engineer · Penz Engineering / ConnexFrame

Civil Engineer (2013). 15+ years in civil construction with focused practice in precast concrete and high-performance envelopes. Sole inventor on the ConnexFrame USPTO provisional patent application.

Conceived the multi-zone architecture, designed the parametric CAD model, fabricated the V1–V3 prototypes, and conducted each of the three validation campaigns on-site — UPF/CETEC for mechanical tests and field for the drone thermography.

This level of personal involvement is a deliberate differential: every datapoint in this dossier can be traced to a witnessed test — in contrast to competitors who operate validation under opaque NDA.

EducationCivil Engineering · 2013

Experience15+ years in the sector

PatentUSPTO Provisional · sole inventor

Validation labUPF/CETEC · ISO/IEC 17025

CompanyPenz Innovative Engineering LLC (US)

Based inOcoee, FL · USA | R&D: Passo Fundo, BR

12 · The Path Ahead

Certification, partnerships, Phase 02 tests.

Academic-first U.S. entry. Honest status on every milestone.

Mar 2026

Thermography

DJI M4T · 13 points · qualitative

Apr 2026

Compression

Emic SSH300 · 6.52 MPa

May 2026

Tension

Schenck · 360.2 MPa

Q3 2026

AC422 Shear

Double-shear · ICC-ES

Q3 2026

AC320 Pull-out

ASTM E488 · anchorage

Q1 2027

ASTM C518

R-value · ISO/IEC 17025

2028 est.

ICC-ES ESR

Commercial use under IBC

Academic partnerships

PLANNED

Utah State University (USU)

Accredited precast lab. Target for AC422 double-shear and durability campaigns.

PLANNED

University of Nebraska-Lincoln (UNL)

Origin of the seminal PCSP thermal-bridge research (Sorensen 2019). Target for ASTM C518 R-value.

ACTIVE

Universidade de Passo Fundo (UPF/CETEC)

Consolidated local partner. Compression and tension already completed.

Phase 02 — next campaigns

ICC-ES Acceptance Criteria 422 · min. 3 specimens · symmetric loading.

ASTM E488 · anchorage capacity · validates failure modes.

Quantitative thermal resistance · ISO/IEC 17025 accredited lab.

Durability for IECC climate zones 5–8 (Utah, Nebraska, Canada, U.S. north).

13 · Why Now

The technology already exists. The market window is open.

A regulatory transition, a concentrated market, and a validated multi-material connector — converging on the same window.

Code-driven demand

DOE determination — 2-year state window

ASHRAE 90.1-2022 §5.5.5 + IECC 2024 §C402.7 require explicit thermal-bridging mitigation across structural penetrations. The DOE’s affirmative determination (6 Mar 2024) obligates states to certify updated commercial codes within two years — driving adoption through 2026 and beyond.

A concentrated market open to a new architecture

A market structurally open to a challenger

Large groups control the U.S. composite-connector market — CRH/Leviat, Dayton Superior/HK, and Owens Corning. Several also own precast plants. No connector publishes open thermography or combines high composite action with a certified thermal break. ConnexFrame is engineered to fit that gap.

Validated and patent-protected

Three campaigns done. USPTO filed.

USPTO provisional patent on file. Physical V1–V3 prototypes fabricated. Compression, tension, and field thermography completed at an ISO/IEC 17025-calibrated lab. ICC-ES AC422 / AC320 pre-application underway.

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One connector. Composite action and thermal break.

A national-scale envelope inefficiency.

A direct contribution to U.S. energy security and federal climate priorities.

Regulation, supply chain, capital — converging on the same year.

ConnexFrame — three-zone multi-material architecture.

Functional geometric separation, by design.

Why separate the functions?

Why this composite (VE + GMB + Basalt)?

Prototypes fabricated. Panels cast. Equipment calibrated.

Three parallel validation campaigns — March to May 2026.

Absence of localized thermal gradients over anchorages.

Five incumbents, one open dataset.

ConnexFrame Designer App — sizing, ROI, benchmarking.

What is protected — and what isn't.

Sole inventor, lead engineer, present at every test.

Certification, partnerships, Phase 02 tests.

Academic partnerships

Phase 02 — next campaigns

The technology already exists. The market window is open.